A-mount (Sony) The lens mount used by Sony’s Alpha SLT cameras. Because these cameras have a mirror in the body, even though it’s a non-moving one, the rear of the lens is further from the sensor, so Alpha mount lenses are physically different to Sony’s E-mount lens range. You can use Alpha lenses on an E-mount camera with a lens adaptor, but not the other way round.
AA batteries AA batteries are used rarely in digital cameras (except in some cheap point and shoot models) but used extensively in external flashguns and battery grips. Alkaline AAs will do in an emergency, but rechargeable NiMH batteries are more cost effective and last longer between charges.
Aberrations These are optical flaws produced by camera lenses and which are largely unavoidable except in the most expensive or the simplest lens designs. They include distortion, chromatic aberration (colour fringing), vignetting (corner shading) and edge softness.
Accessory shoe This is the technically more accurate name for a camera’s ‘hotshoe’. These days, they’re used for more than just attaching a flashgun, and may be used for external microphones, video lights or electronic viewfinders.
ACROS (Fujifilm) Black and white film simulation mode added to newer Fujifilm cameras. It’s designed to give richer, more intense tonal rendition than the regular monochrome film simulation.
Action camera A small, simple and largely automated video camera (you can also shoot stills) designed to attach to a helmet, handlebars, surfboard or any other kind of object and provide dramatic first-person video of adventure sports and other activities. Almost all use fixed focal length super-wideangle lenses and shoot full HD video – some can shoot 4K.
Active D-Lighting (Nikon) An exposure mode on some Nikon digital cameras which balances up the exposure in high-contrast scenes. The camera reduces the exposure to make sure it captures bright highlight detail and then processes the image to brighten up dark shadows. It can be applied in different strength settings.
Adjustment Brush (Lightroom) A tool used to ‘paint’ adjustments on to an image manually, and one of the key adjustment tools in Lightroom, for example. You can choose the adjustments you want to make, e.g. exposure, saturation, clarity and so on before you start painting, or make changes to these settings afterwards too.
Adjustment layer A special type of layer in image-editing software which is designed to hold adjustments rather than other image layers. It's a way of 'stacking' a series of adjustments to an image without affecting the image layer itself.
Adobe Bridge The folder and file browser used across Adobe's Creative Cloud applications, not just Photoshop. For many photographers, its a simpler and more predictable image organizing tool than Lightroom.
Adobe Camera Raw Software that works alongside Adobe Photoshop to open and process RAW files before they open in Photoshop itself. Adobe Camera Raw’s tools are also built into Adobe Lightroom. Most people use Adobe Camera Raw to process their RAW files simply because they’re using Photoshop or Lightroom, but other RAW converters are available.
Adobe ProPhoto RGB This is a wide-gamut 'working space' used in Lightroom and other Adobe software. The idea is that it encompasses all the lesser working spaces you might need to produce images in, such as sRGB or Adobe RGB.
Adobe RGB This is a professional colour space offered by more advanced cameras and it captures a slightly wider range of colours than the usual sRGB colour space used by most consumer devices. It can be useful if pictures are destined for commercial print production, but it does introduce complications with colour profiles and monitor calibration.
AE-L/AF-L button AE/AF lock is used to fix exposure settings and focus point before taking a photo, offering flexibility in camera control.
AF-P lens (Nikon) This is a new autofocus technology being introduced by Nikon in its consumer-level lenses. It used different autofocus actuators to its existing AF-S (Supersonic Wave) lenses. The AF-P system uses stepper motors for a fast, quiet and smooth autofocus action that's especially well suited to video, where you don't want fast, sharp focus movements or audible motors that you can hear in the video.
AF-S lens (Nikon) This is the most common autofocus system in current Nikon D-SLR lenses it uses Silent Wave ultrasonic autofocus actuators to produce very fast and quiet focusing well suited to stills photography.
AF Assist In dim lighting the camera’s autofocus system may struggle to lock on to your subject, but on some cameras a lamp on the front of the camera will light up in low light and shines a bright, tightly focused beam of light at your subject to help the autofocus system lock on. Not all cameras have or need this kind of focus assistance.
AF coverage Digital cameras use an array of AF points (focus points) to cover different areas of the frame, but they don’t necessarily cover all of it. The AF coverage is the percentage of the frame width and height that contains focus points. Wider coverage is a selling point.
AF fine tune Most cameras use the main sensor for focusing, but digital SLRs have a different system. They use a separate phase detection autofocus sensor which must be precisely aligned with the main sensor for the focus to be accurate. Sometimes this and different lens designs can lead to small misalignments and slight focus errors, so more advanced DSLRs have an autofocus fine tune feature to correct any discrepancies.
Affinity Photo For a long time Adobe Photoshop has been the only real professional level image-editing program, but software company Serif has launched a professional photo editing program which competes directly with Photoshop at a much lower price – and for a single payment rather than the software subscription system introduced by Adobe. Affinity Photo has been built from the ground up for speed and performance and compatibility with the Photoshop PSD file format.
AF points An area on the screen where the camera can check for sharp focus. Typically, the more focus points the better because this gives you more choice about where to focus and usually indicates a faster and more sophisticated focus system.
AI (Artificial Intelligence) Machine-based learning which interprets the contents of the image in a sophisticated way to produce better enhancements or better object and scene recognition. Skylum’s Accent – AI Filter in Luminar uses artificial intelligence to optimize photos automatically, while Google Photos uses artificial intelligence to identify and search through your pictures.
Alkaline battery Alkaline batteries are the most common form of disposable batteries. They last longer than older zinc oxide batteries but are still not ideal for many photo products as they have limited capacity.
Alpha (Sony) ‘Alpha’ is generic name still used by Sony for all its interchangeable lenses, but it also refers to the older Alpha range of SLT cameras. This can be confusing. Sony has made cameras in two types – SLT (single lens translucent) and mirrorless models. Both are Alphas, but the Alpha A9 (mirrorless) and Alpha A99 II (SLT) are entirely different cameras with different lens mounts and lens ranges. Sony’s SLTs use Alpha A-mount lenses, while the mirrorless models use E-mount lenses.
Aluminium (tripods) Cheaper tripods use aluminium legs which keeps costs down but does add to the weight. This isn’t usually a problem if you’re travelling short distances or working from the back of your car, but if you’re taking a travel tripod on a vacation or hiking any great distance, a more expensive carbon fibre tripod will give a better balance between rigidity and weight.
Analog A term now used to design old-fashioned chemical processes to capture images rather than digital – so you can get ‘analog’ cameras, ‘analog’ films and ‘analog’ image effects which replicate the look of these old processes.
Analog A term now used to describe old-fashioned chemical processes to capture images rather than digital – so you can get ‘analog’ cameras, ‘analog’ films and ‘analog’ image effects which replicate the look of these old processes.
Angle of view This is quoted in degrees, and indicates how much of a scene a lens takes in. Wideangle lenses have a wide angle of view, telephoto lenses have a narrow angle of view. Angle of view is directly related to a lens’s focal length, though the different ‘crop factors’ of smaller sensors means that the relationship between angle of view and focal length is different on different-size sensors.
Anti aliasing filter Another name for the ‘low pass’ filter fitted in front of most camera sensors. It’s designed to prevent digital artefacts such as moiré patterns and colour fringing caused by interaction between fine linear or rectangular patterns in real-world subjects and the camera’s rectangular grid of photosites.
Aperture (lens) Aperture is the adjustable lens hole controlling light passage and exposure, with set values across cameras. It influences depth of field and lens 'bokeh'.
Aperture blades The adjustable hole in the lens diaphragm is created by a set of overlapping metal leaves, or ‘blades’. The greater the number of blades, the rounder the hole created and the better the lens’s ‘bokeh’ in out of focus areas. Aperture blades are often curved, too, to enhance that circular shape.
Aperture priority (A) mode This is an exposure mode on more advanced cameras where you choose the lens aperture yourself and the camera then sets a shutter speed that gives you the correct exposure. This gives you creative control over depth of field, for example, without losing the convenience of automatic exposure.
Apochromatic (APO) lens An apochromatic (APO) lens is designed to offer improved correction of chromatic aberration and spherical aberration using specialised materials and combinations of lens elements. It’s a selling point for lenses, though only indicates the lens design used and isn’t really a guarantee of good performance on its own.
APS-C sensor This is the most common sensor size in cameras designed for enthusiasts and experts and it’s found in consumer DSLRs, mirrorless compact system cameras and some high-end compacts. APS-C sensors are around half the size of a full-frame sensor or the 35mm negative, and measure approximately 24 x 16mm. They have a crop factor of 1.5x, which means that you have to multiply the lens’s focal length by 1.5x to get its effective focal length in 35mm/full frame camera terms.
APS-H sensor This is a relatively uncommon sensor size mid-way between APS-C and full frame. Canon used it for its EOS-1D high-speed pro sports/press photography DSLRs before these were merged with the introduction of the full frame EOS-1D X. Canon has since announced the development of a 250MP APS-H format sensor, though this has not yet been used in any commercial product.
Arca Swiss Many tripod heads come with quick release camera plates, and while some are specific to that tripod maker and tripod, which can be annoying, Arca Swiss plates use a standard design that means they should be interchangeable across tripod brands. It’s a good selling point in a tripod head.
Area AF This is a focus mode where the camera automatically selects a focus point, usually choosing the object closest to the camera. It's an effective 'standby' autofocus mode.
Artefacts Any unwanted digital flaw in a photo, such as exaggerated sharpening and edge 'halos' around objects, banding or 'posterisation' due to excessive image manipulation or sensor spots exaggerated by localised contrast or HDR processes.
Aspect ratio This the picture's proportions as width versus height. DSLR sensors have a 3:2 ratio, so that photographs are 3 units wide to 2 units high. Most compact camera sensors have a slightly squarer 4:3 aspect ratio. It doesn't matter what the units are – the ratio stays the same, so a photo could measure 3 inches by 2 inches or 6 meters by 4 meters and still have the same 3:2 aspect ratio. You can shoot in different aspect ratios by cropping the sensor area. HD video is shot in a wider 16:9 ratio.
Asset management The professional term for image cataloging, and often used in photographic or design studios managing large numbers of images on a commercial basis. They may include not just photos but illustrations, logos and other graphics, hence ‘assets’ rather than photos.
As shot (white balance) When you shoot RAW files you will be able to change the white balance setting later, but the camera will still store shooting settings you chose in the RAW file. When you open the RAW file in your software, it will read this embedded data and display it as ‘As Shot’ in the white balance settings. You can adjust the settings or apply a new white balance preset, and the ‘As Shot’ setting embedded in the file will still be available if you need to return to it later.
Astia (Fujifilm) Astia is a transparency film made by Fujifilm, and now incorporated into its digital cameras' film simulation modes. The digital version has similar saturation to Velvia but softer contrast and less obvious color shifts.
Auto exposure Where the camera measures the light and sets the shutter speed and/or lens aperture on its own.
Autofocus Practically all cameras have automatic focusing systems where they can check the focus at different points around the frame and then adjust the lens’s focus so that that point in the scene is precisely in focus. You can let the camera choose the autofocus (AF) point automatically or select it yourself (manual AF point selection). The autofocus system will either operate once only before you take the shot (single-shot AF mode) or constantly if you’re using the camera’s continuous shooting (burst) mode (continuous AF mode).
Auto ISO On simpler cameras the Auto ISO option simply increases the ISO setting in poor light to keep shutter speeds high enough to avoid camera shake. On more advanced cameras you can program in both the maximum ISO you want to use and the minimum shutter speed, which makes Auto ISO much more useful.
Auto mode A simple shooting mode offered on almost all cameras. In this mode, the camera automatically takes care of all the settings, from exposure to focusing and (usually) flash.
Auto white balance This is where the camera measures the color of the light in a scene and attempts to correct it so that the color is neutral – the color is balances so that white will appear as white.
Averaged metering This is a very simple type of exposure reading where the camera’s light meter just measures the total amount of light in the whole scene. It often leads to underexposure because bright areas in the scene have a disproportionate effect. Today’s digital cameras offer a range of more sophisticated exposure metering patterns and only a few still over averaged metering amongst these – some photographers still like it because although it’s a crude way of measuring the light, it’s quite predictable and easy to interpret.
Axial chromatic aberration Axial chromatic aberration is colour fringing that appears around out of focus objects. It happens when the lens defocuses different colours differently, e.g. blue goes out of focus more quickly than other colours and creates a soft blue fringe round out of focus objects.
Back button focus Using a button on the back of the camera to activate autofocus, not the shutter button.
Back illuminated sensor A newer type of sensor where the circuitry has been moved to the back so that the light receptors on the front are unobstructed. This gives a modest but useful improvement in light-gathering power, digital noise and overall image quality, but it’s not the dramatic technical leap that manufacturers often suggest.
Backlighting This is where the lighting for the scene shines directly towards the camera and through or around the subject. It can make the exposure difficult to work out because the camera’s light meter needs to work out whether to set the exposure for the bright background or your subject, but it produces striking lighting effects. With portrait subjects it gives attractive ‘rim-lighting’ effects around the hair and it can give transparent or translucent subjects like stained glass windows a rich, luminous colour.
Backpack Backpacks are designed for carrying a large quantity of camera kit over some distance. They’re also good for packing kit for travel. On the downside, they are bulky and don’t offer very quick access to cameras and lenses, so they’re not ideal for casual ‘walk around’ photography.
Backup It’s extremely important to keep backups of your images, the changes you've made to them and your image organization system. There are backup tools for backing up your entire computer system, selected folders and sub folders, and backup tools built into image cataloging programs like Lightroom.
Ball head A ball head is a tripod head where the camera movement is locked with a single lever. The camera is mounted on a post fixed to the ball and when the head is slackened off the ball can move freely in any direction.
Barrel distortion This is where straight lines near the edge of the picture appear to bow outwards, and you see this a lot with zoom lenses at their wideangle setting. It’s most noticeable if the horizon is near the top or bottom of the picture. Barrel distortion is very difficult to eradicate completely from the lens design, but it can be fixed using software, and some cameras now have distortion correction built in. It’s one of a number of common lens aberrations. Telephoto lenses often show the opposite effect, ‘pincushion distortion’.
Batch processing Applying the same image adjustments to a whole batch of photos. For example, you might choose a black and white conversion style and apply it to all the photos from a particular shooting session. Batch processing can save a lot of time, but only if all the images will benefit from the same settings.
Batteries Most cameras use dedicated rechargeable lithium-ion cells, but some accessories like external flashguns, battery grips and hotshoe mounted LEd panels use regular AA cells instead.
Battery charger A battery charger is a separate device plugged into a mains wall socket. You remove the battery from the device and plug it into the charger for recharging.
Battery grip This is an accessory that attaches to the bottom of some DSLRs and mirrorless cameras. It provides a longer battery life for long periods of shooting and it’s popular with sports and action photographers taking lots of shots in continuous shooting mode. Battery grips often have duplicate controls for shooting with the camera in a vertical position, which also makes them ideal for busy portrait and fashion photographers.
Battery life This is usually quoted as the number of shots you can expect to be able to take before the camera’s battery runs out. Compact cameras may only be able to take a couple of hundred pictures, while a DSLR might be able to take a thousand. Battery life is normally quoted using the CIPA standard so that battery life can be compared in standardised conditions.
Bayer sensor Most camera sensors use a single layer of photosites (pixels). These are only sensitive to light, not colour, so a mosaic of red, green and blue filters (the 'bayer pattern') is placed on top of the sensor's photosites so that individually they capture red, green or blue light. When the camera processes the sensor data to produce an image, it ‘demosaics’ the red, green and blue data, using colour information from surrounding photosites to ‘interpolate’ full colour data for each pixel.
Bayonet mount A twist-lock mechanism used almost universally for mounting lenses on camera bodies. You line up two dots, one on the lens barrel and one on the camera body and insert the lens, then twist the lens in the mount until it locks into place. The lens is released again by pressing a button on the camera body to release a catch, then twisting and removing it.
The Big Stopper is a powerful 10-stop neutral density filter from Lee filters. The name has caught on and many now refer to high powered ND filters as 'big stoppers'. The point of an ND filter is that it reduces the light passing through the lens and allows long exposures even in bright daylight. This is the technique used to create blurred water and cloud effects in landscapes.
Bits and bit depth ‘Bits’ are the basic building block of digital data, and the more bits of information used in digital images, the subtler the colours and tonal transitions. Bits and pixels are related, in that the greater the ‘bit-depth’ used to create a pixel, the better the quality of the colour/tone information in that pixel. Digital cameras typically capture 10, 12 or 14 bits of data for each pixel, and this is then processed down to produce regular JPEG photos (8 bits) or converted into high-quality 16-bit TIFF files.
Black and white Technically, black and white should be ‘less’ than colour, but its popularity is, if anything increasing. Black and white suits some subjects extremely well, drawing more attention to shapes, lighting and composition than is generally possible with colour photography. Most cameras have black and white picture modes, which is very useful when you’re composing images, but you get more control over the results by converting colour images to black and white on a computer later, so it’s a bit of a dilemma which route to take.
Black and white filters It might seem strange that black and white photographers use coloured filters, but there is a reason for this. When you shoot in black and white, the camera or the film is converting different colours into shades of grey. When you use a coloured filter, you’re shifting and changing the brightness of the different colours in the scene, and this changes their shade of grey in the photograph. This is why they’re sometimes called ‘contrast’ filters too. For example, a red filter allows red light through but blocks light of other colours. Anything red in the scene becomes proportionally much brighter, anything opposite to red, like a blue sky, comes out a much darker shade of grey – nearly black, sometimes.
This is a kind of modern-day soft focus filter that takes a different approach. Black mist filters are designed to reduce contrast and soften harsh highlights in portrait shots, and at the same time soften wrinkles, spots and other unwanted facial blemishes.
Blend mode Blend modes are used to control the way different layers in an image interact, and they apply not just to other image layers but also non-destructive adjustment layers.
Bokeh This is a Japanese word to describe the particular visual quality of out of focus areas in a picture. You might think it hardly matters what things look like when they’re out of focus, but there’s a bit more to it than that. ‘Bad’ bokeh produces unnatural-looking outlines and highlights, while ‘good’ bokeh looks ‘creamy’, smooth and natural. Good bokeh is associated with the shape of the diaphragm in the lens – more aperture blades and rounded aperture blades produce a more circular shape and better bokeh. Some photographers confuse bokeh with how out of focus a subject is, but that’s not the same thing. A lens with a wide maximum aperture can make background objects extremely defocused, but that doesn’t mean they have good ‘bokeh’.
Bounce flash This is a feature on more advanced external flashguns which lets you swivel and tilt the flash head in different directions, so that you can 'bounce' it off walls, ceilings, reflectors and other surfaces. This gives a much softer, more directional light than regular flash.
Boundary Warp (Lightroom) A tool in Lightroom that fills in the blank wedges at the edge of a panoramic image stitched together from overlapping frames. Normally, you’d have to crop these off and lose parts of the picture, but the Boundary Warp tool ‘pushes’ parts of the picture out to the edges so that you don’t lose anything.
Bracketing Taking the same shot at a series of different exposures with the intention of choosing the best one later or merging them together to create an HDR image. Most cameras offer an auto exposure bracketing option. You choose the bracketing interval (the difference between the exposures, typically 1EV) and the number of frames (usually 3, sometimes 5 or even 7). Some cameras offer other types of bracketing, e.g. white balance bracketing or even focus bracketing.
Bridge camera This is a compact camera with an extremely long zoom range, sometimes as much as 50x, 60x or more, and designed to act as a ‘bridge’ between regular compact digital cameras and digital SLRs. The lens can’t be swapped, though, and bridge cameras (mostly) have small sensors, which restricts the picture quality.
Brightline frames Framing guides in direct vision viewfinders which show the area that will be captured by the lens – with interchangeable lens cameras there may be frames for different lens focal lengths. The frames are designed to catch the light and appear 'bright'.
Browser (photos) Software that can ‘browse’ through the folders on your hard disk and show you any photos inside them as thumbnail images. This is the simplest form of photo organization tool and works perfectly well for many photographers, even though it lacks flexibility. Adobe Bridge is a file browser, for example, while Alien Skin Exposure and ON1 Photo RAW are examples of photo-editing programs that have browsers built in.
Buffer The 'buffer' is short-term internal memory used by the camera to store image data captured by the sensor while it’s waiting to be processed and saved to the memory card. It becomes important in the camera’s continuous shooting mode because the camera can capture photos faster than it can save them, so before long this buffer fills up. The larger the buffer, the longer you can keep shooting.
Burst mode This is another name for ‘continuous shooting’ mode and it’s the term used by cheaper point-and-shoot cameras – though it’s actually the same thing. In this mode, the camera keeps taking pictures all the time you hold down the shutter button, right up until the time you release the button or the camera’s internal memory buffer fills up and it has to stop to process and save the pictures to the memory card.
C-AF (continuous autofocus) In continuous AF (autofocus) mode, the camera continually refocuses all the time you have the shutter button half-pressed or fully-pressed. It's used in continuous shooting mode to keep moving subjects in focus as you follow them with the camera. Continuous AF mode may include subject tracking or predictive autofocus capability.
Cache This is temporary storage space used by software so that files you need often can be accessed more quickly. It’s typically used for image thumbnails and previews in programs like Adobe Bridge and Lightroom. Sometimes cache files cause problems and must be purged or deleted, sometimes the storage allocation for the cache needs to be made larger in the application preferences to improve performance. Caches and cache files are generally expendable, but they are there for a reason and to speed up performance.
Camera bags These are designed specifically for holding camera gear, with a padded interior separated into compartments with padded dividers which you can usually rearrange to suit your kit. Camera bags fall into a handful of main types: backpacks, shoulder bags, messenger bags, slings, holsters, roller bags and hard cases.
Camera calibration Using color management tools to measure the color response of a camera and then generating a profile to correct the camera's colors. It's related to the use of profiles for image effects in programs like Lightroom, but designed more for correction rather than achieving a particular 'look'.
Camera shake This is image blur caused by camera movement during the exposure. The longer the exposure (the slower the shutter speed), the more time there is for camera movement to take place. Any movement is also exaggerated with longer focal length lenses (telephotos). There is a simple way to estimate the risk of camera shake – take the effective focal length of the lens and divide it into 1 to get the minimum ‘safe’ shutter speed. So with a 30mm lens, the minimum safe shutter speed would be 1/30sec. However, today’s image stabilisation systems reduce shake and make slower shutter speeds possible.
Camera types Digital cameras come in a multitude of different types and sizes, and some of the jargon can be quite unhelpful. For example, 'compact' cameras aren't necessarily compact and the real difference is that they have non-removable lenses. DSLRs and CSCs are both examples of interchangeable lens cameras, or ILCs, and these are differentiated by their design, sensor size and intended market. Most novices start off with a compact camera, move up to a DSLR or CSC when they become enthusiasts and then upgrade to a full-frame or medium format camera if they turn professional.
Carbon fiber (tripods) Carbon fibre is very light and very strong, so it's popular in the tripod market, where balancing weight and rigidity is especially important. Carbon fibre is expensive, however, so many tripod makers offer both aluminium (cheaper but heavier) and carbon fibre versions of their tripods. Usually the carbon fibre is used only in the legs. Even on carbon fibre tripods, the 'spiders' (the plate where the legs are joined at the top) are usually cast from metal alloys, as are tripod heads.
Card reader Device used for easily transferring photos from a memory card to a computer. Card readers plug into a computer’s USB port and have slots for inserting memory cards. When the card is inserted it appears on the computer’s desktop as an external disk drive. It’s then an easy matter to copy photos across to the computer. Many computers how have card readers built in.
Cataloguing software Software designed to organize large collections of photos using an internal database that speeds up searches and lets you create ‘virtual’ albums and smart albums without actually having to move images on your hard disk. Adobe Lightroom is a good example, using a database ‘catalog’ to organize search and display images. Cataloging software is more complex and powerful than image ‘browsers’ like Adobe Bridge, which simply show you the contents of folders on your computer.
Cataloguing software Software designed to organise large collections of photos using an internal database that speeds up searches and lets you create ‘virtual’ albums and smart albums without actually having to move images on your hard disk. Adobe Lightroom is a good example, using a database ‘catalog’ to organise search and display images. Cataloguing software is more complex and powerful than image ‘browsers’ like Adobe Bridge, which simply show you the contents of folders on your computer.
CCD An older type of digital camera sensor still used on a few specialised cameras but now mostly replaced with more efficient CMOS sensors. These produce less heat and noise and are better suited to use in cameras with full time live view and video features.
Center column The main part of a tripod is the three legs, but most also have a centre column that extends upwards still further for extra height. Some tripods have removable centre columns and with some Gitzo tripods they are optional extras. The advantage of removable columns is that get the camera closer to the ground for low angle shots, or replace them with different types, such as short columns or geared columns. In some cases the centre column is on a hinged mechanism so that it can be rotated and used as an angled boom for overhead shots or close-ups.
Center weighted metering This is one of the various light metering patterns offered on most digital cameras. It’s a relatively crude system which averages the light across the whole scene but gives special emphasis to the centre. It’s less reliable for for novices shooting in a wide variety of conditions, but its simple response to scenes actually makes it easier for more experienced photographers to interpret the results.
CFA (color filter array) This is a grid of tiny filters placed over a sensor so that each photosite captures only red, green or blue light. This is the only way a single-layer sensor can be made to capture full color images. The most common arrangement is the Bayer array.
CFast CFast cards resemble Compact Flash cards physically, but they use a different data bus and a different set of pins. They are not physically compatible. They offer faster data transfer rates than regular Compact Flash cards and have been used in some high end video cameras, for example.
CFexpress CFexpress cards are a new format for very high speed data capture. They are physically identical to the XQD cards currently in use in some cameras – many cameras which use XQD cards are expected to get firmware upgrades to get CFexpress compatibility. CFexpress looks set to become a major high speed card format of the future.
Channels The data used to create digital photos is split up into three colour ‘channels’ – red, green and blue, or ‘RGB’. These are then mixed to produce the millions of different colours required for lifelike pictures. In commercial printing, this red, green and blue (RGB) colour model is swapped for cyan, magenta, yellow and black (CMYK), which are the four colours used by commercial printing presses.
Chromatic aberration This is a lens aberration that produces colour fringing around the outlines of objects near the edges of the picture. It’s very hard to eradicate completely from lens designs without making them extremely complex or expensive, but it is possible to correct chromatic aberration using software and many cameras will now correct it automatically as they process the image.
Cinema 4K (DCI 4K, C4K) This is a version of 4K video with a slightly wider aspect ratio than 4K UHD and is actually 'true' 4K with a resolution of 4,096 x 2,160 pixels. The aspect ratio is slightly wider than the 16:9 ratio widely used in video, so it's not suitable for all productions. Not all cameras that capture 4K UHD can capture C4K.
CIPA CIPA stands for the Camera and Imaging Products Association, an independent body which reports on the state of the camera industry and sets up standards for measuring different aspects of camera performance, notably battery life. When a camera quotes CIPA after the battery life, you know it’s been measured in standardised conditions and it can be compared directly with the battery life of other cameras that quote the CIPA test in their results.
Circle of confusion This is a concept used in calculating depth of field. When a point is slightly out of focus it's rendered as a circle instead, but as long as this 'circle of confusion' is small enough, it still looks like a point.
Clarity 'Clarity' is a localized contrast adjustment much coarser than regular sharpening, which throws larger objects into sharp relief and can add some much needed definition and 'bite' to low-contrast scenes.
Class rating (memory cards) SD/SDHC/SDXC memory cards are given a 'class' rating to indicate how well suited they are to video capture, where a minimum sustained write speed is essential. Lower spec cards may have a Class 4 rating, better cards may be Class 6 and you need a Class 10 card or better for capturing 4K video.
Clipping For photographers, ‘clipping’ is where the image histogram is cut off abruptly at one or both edges. It means that some image detail is completely lost in solid black shadows (shadow clipping) or completely white highlights (highlight clipping).
Cloning Using a special clone stamp tool to copy pixels from a nearby area of an image to cover up an unwanted object or blemish. Cloning is something of an art, and some programs now offer simpler ‘content aware’ object removal.
Cloud storage Where you store or share images online as well as or instead of storing them on your computer. Cloud storage offers the advantage that your images are accessible everywhere as long as you have an Internet connection, though displaying and downloading images is of course slower than opening them on a hard drive, and uploading images in the first place is slower still. Examples include Apple iCloud, Dropbox and Google Drive.
CMOS This is the most common type of sensor in today’s digital cameras. One of its main advantages is its lower heat output compared to the CCD sensors used in the past. This makes it particularly suitable for cameras with larger sensors and mirrorless cameras where the sensor is always ‘on’.
CMYK This is a color model used in printing processes, where colours are defined in terms of cyan, magenta, yellow and black colour channels (black is represented by the letter ‘K’). Desktop printers use CMYK inks but carry out the conversion from regular RGB photos automatically. In commercial printing, a designer will convert a regular RGB photo to CMYK to check the color rendition and prepare it for printing.
Color burn A layer blend mode found in most programs that support image layers. Using this mode produces an ultra-high contrast composite image based on the layer it’s applied to and the layer(s) underneath.
Color Efex (Nik Collection) A software plug in that’s part of the DxO Nik collection. Color Efex Pro offers a huge variety of preset image effects you can browse through and apply to your photos with a single click, but you can also adjust the filters manually and even stack them to create custom ‘recipes’. Color Efex Pro also offers localized adjustments via ‘control points’.
Color management For designers and professional photographers it’s often important to maintain consistent colour rendition from the camera, through to the computer display used for browsing and editing photos and right through to the final output device, generally a printer. Colour management tools use software ‘profiles’ and hardware monitor calibration and printer calibration devices to try to ensure this consistency of colour. It’s a complex process, and it’s worth pointing out that when images are going to be displayed on a screen rather than being printed, you have no control over the colour rendition of the output device. Many photographers don’t use colour management at all.
Color model This is the system used by computers and other digital devices for defining colours. In photography, the RGB system is almost universal – colours are defined using red, green and blue colour ‘channels’. In printing, it’s CMYK, or cyan, magenta, yellow and black. Some image-editing processes use Lab mode, which consists of a ‘lightness’ channel and two (‘a’, ‘b’) colour channels.
Color noise One of the two types of digital image noise and caused by random variations in the colour of neighbouring pixels. Colour noise is relatively easy for software to remove without any significant impact on the image quality. Luminance (contrast) noise is the other type, and much more difficult to remove effectively.
Color sensitivity This is a property sometimes used in black and white conversions from a color image. You’ll find it in programs like Silver Efex Pro, Capture One and others, and it changes the way different colors are converted into shades of gray. For example, you can use it to mimic the effect of a red filter in black and white photography, by reducing the strength (sensitivity) of the blue/cyan colors in the image and increasing the strength of the red/orange tones. In the old days, you’d use the Channel Mixer in Photoshop to achieve the same thing in a cruder fashion; these days, black and white conversion tools offer a wider range of colors.
Color space Different devices can’t always display the same range of colours, so your camera may be able to record a wider range of colours than your computer monitor or tablet can display, for example – in other words, the monitor offers a smaller ‘colour space’. To get round this, there are two main RGB colour spaces you can work on. The sRGB colour space is a smaller, universal colour space that practically any device can match. Adobe RGB is a larger colour space that your camera and printing systems can capture but your monitor probably can’t, which means some complex workarounds and pitfalls and really needs a switch to a more complex colour managed workflow. sRGB is the simplest solution, and (though some will debate this) you’re unlikely to see any real advantage to Adobe RGB in everyday photography.
Color temperature A traditional technical measurement for the white balance setting that uses temperature values in degrees Kelvin rather than named presets like ‘Direct Sunlight’, ‘Cloudy’ and so on. Colour temperature is used for choosing and controlling the colour of photographic lighting equipment and you can use it an alternative to white balance presets on more advanced cameras.
Commander mode (Nikon) A flash control mode on some Nikon DSLRs and external flashguns (Speedlights) which can fire other Speedlights remotely via infra-red. It’s possible to control quite complex lighting setups in this way, and it’s part of Nikon’s CLS (Creative Lighting System).
Compact camera You might imagine that this refers to smaller, pocket-sized cameras but the definition is a little wider than that and includes any camera with a fixed (non-interchangeable) lens. ‘Compact cameras’ include regular point-and-shoot compact cameras, high-end compacts and bridge cameras.
Compact Flash An older, larger memory card type still used in many professional cameras. It’s around twice the size of the more recent SD card format and thicker too. Compact Flash memory card capacity is measured in the same way in GB (Gigabytes) but speed standards may vary, especially for video use. Professional CF cards offer the same speeds and capacities as pro SD cards.
Compact system camera (CSC) Another name for ‘mirrorless’ cameras and used to distinguish them from digital SLRs. They are ‘system’ cameras in that they take interchangeable lenses and accessories – just like a digital SLR. However, they don’t have a DSLR’s mirror mechanism, and this ‘mirrorless’ design makes them more compact.
Composition This is the art, or skill, of arranging the objects, perspective and framing of a photograph to achieve the desired visual effect. There are a number of 'rules' of composition, including the rule of thirds, the Golden Mean and various other photographic truisms that may or may not prove useful.
Compression A software process that reduces the storage space taken up by photo or video image files. It comes in two type: ‘lossless’ and ‘lossy’ compression. Lossless compression is used by TIFF files, for example and retains all the image data but does not produce the biggest savings. Lossy compression is used for the JPEG format and produces much smaller files, but some data is lost in the process – though this may not be visible in real-world viewing conditions.
Content aware Adobe image repair tools that can ‘intelligently’ paint over unwanted objects and blemishes using surrounding image data matched to the area being covered up. Photoshop has content-aware repair tools, Affinity Photo offers an Inpainting brush.
Continuous shooting In this mode the camera keeps taking pictures for as long as you hold down the shutter release button. The speed it can take them is the continuous shooting speed, which is quoted in frames per second (fps), and the number the camera can take is determined by the size of the image files, the quality setting (JPEG or RAW) and by the camera’s internal memory buffer capacity.
Contrast Contrast, in its simplest sense, is the difference in brightness between two tones. In photography it's usually taken to mean the brightness range of a picture – the difference in brightness between the brightest and darkest parts of a picture.
Contrast AF A relatively simple autofocus system that measures the contrast around the edges of objects and then adjusts the focus to see if the contrast goes up or down. When the contrast is highest the subject is in focus. Contrast AF is accurate because it uses the image being captured by the sensor itself, but because it uses trial and error it’s not as fast as phase detection autofocus, the system used by digital SLRs and an increasing number of mirrorless compact system cameras (CSCs).
A color filter used in black and white photography to change the shade of grey that colors are reproduced as. They're called 'contrast' filters because they can change the contrast (in shades of grey) between different colors.
Control Point (DxO) A special selection and adjustment tool used by the Nik Collection plug-ins and DxO PhotoLab, control points operate over an adjustable circular radius and select only tones similar to the area under the central target. You can use them to adjust Brightness, Contrast, Structure, Saturation and more.
Converging verticals A type of perspective distortion caused by tilting the camera upwards to photograph tall buildings. It's worse with wideangle lenses because they let you stand closer, so you tilt the camera even more. The only solution is to compose the shot with the camera completely level.
Copyright You own the copyright in any photo you take, though if you photograph a model or an important building, you may not have the right to use your photos commercially without their permission (or ‘release’). Some cameras can embed copyright information.
Corner shading Corner shading is another term for vignetting, where the edges of the picture are darker than the center. It's because the lens is illuminating the sensor unevenly, and most camera lenses have optical designs that reduce or eliminate this vignetting effect.
Creative Cloud (Adobe) Adobe’s online image sharing, storage, synchronization and collaboration service. Many of Adobe’s workflow tools now rely on its Creative Cloud services.
Creative Lighting System (CLS) (Nikon) Wireless flash system used by Nikon to control one or more external Speedlights from one place. Speedlights can even be combined in 'groups' for more power or more sophisticated lighting effects.
Crop factor Used to work out the effective focal length of lenses on cameras which don't have full frame sensors. You multiply the actual focal length by the crop factor to get the effective focal length. The crop factor of an APS-C camera is 1.5, so a 50mm lens has an effective focal length of 75mm.
Crop mode Many lenses designed for APS-C format cameras can be used on larger full frame cameras, but because the lens image circle is designed for a smaller sensor the camera will switch to a 'crop mode' that only uses this smaller area on the sensor.
Cropping Trimming images to remove unwanted detail at the edges or make them fit the aspect ratio of screens or specific printing papers or to improve the composition of a photo.
Crop sensor A 'crop' sensor is one that's smaller than a full frame sensor. This means that it captures a smaller area and a narrower angle of view with the same focal length lens. In effect, smaller sensors make lenses look as if they have a 'longer' focal length, and by a specific factor – or 'crop factor'.
Curves Curves are one of the most fundamental image adjustment tools in photo editing software. They're used to shift different parts of the picture’s tonal range to make them darker or lighter, though they can also be used for color adjustments.
Custom white balance This is where you use the camera to take a picture of a neutral tone, such as a 'grey card', and then create a custom white balance preset to 'neutralise' the colour of the light.
Cutout Where an object in a photo is cut out from its surroundings using a selection or a mask so that it can be added to another image or placed against a plain (usually white) background.
D-Lighting (Nikon) Exposure adjustment tool offered in some Nikon software for brightening the darkest parts of a picture without altering the rest. It's a less advanced version of the Active D-Lighting system built into Nikon cameras. Regular D-Lighting just brightens the shadows – it's too late to adjust the exposure at the software stage.
Dehaze This is a relatively new tool in Lightroom and other programs. What the Dehaze effect does is to split the image up into different tonal areas – such as the sky and the foreground in a landscape photo – and then maximise the contrast within these areas. The effect is strongest in areas which are quite pale and washed out, such as weak skies or distant hazy horizons.
Demosaicing Process where the camera (or RAW conversion software) takes the 'mosaic' of red, green and blue pixel data from the sensor and converts it into full-colour information.
Depth of field Depth of field refers to the sharpness of an image, both near and far. Factors influencing it include lens focal length, aperture, and focus distance.
Depth of field preview Usually you view the scene with the camera lens wide open and it only stops down to your chosen aperture the moment you press the shutter button, so it’s hard to judge just how much depth of field the final photo will have. The depth of field preview stops the lens down to the taking aperture, though, so you can judge the effect in the viewfinder or on the LCD display.
Device profile A device profile is used to correct the colors produced by a device to be consistent with those of other devices in your workflow. In a 'color managed' system you might use a monitor profile for your computer monitor and a printer profile for your inkjet printer.
Dfine (Nik Collection) Software plug in for reducing noise in images and part of the Nik Collection. Like many other noise reduction programs, Dfine analyzes the image and calculates a noise reduction profile. It’s also possible to define the areas used for analysis manually.
Diaphragm Mechanism inside a lens which uses interlocking metal leaves, or 'blades', to produce a variable-sized aperture within the lens. This is used to control the amount of light passing through and hence the exposure.
Diffraction Diffraction is a softening effect you see at very small lens apertures. It's caused by the way light bends when it passes a sharp edge (the edges of the aperture diaphragm blades), and it's worse at small lens apertures because a higher proportion of the light is bent compared to a relative small proportion passing unchanged through the center of the aperture.
Digital stabilization This is where camera movement is counteracted digitally. It's not very effective for stills photography, where it's sometimes called 'electronic stabilization', but it can be very useful in video, where it can smooth out or remove camera movement between frames.
Diopter adjustment A small knob or lever next to the viewfinder which you use to adjust the focus of the eyepiece to match your own vision. The information in the viewfinder should appear sharp without you having to strain to bring it into focus.
Direct vision viewfinder A viewfinder that's separate to the camera's lens and shows a view of the scene 'directly'. These are found on many older cameras and a few current models. The framing is less accurate, but direct vision viewfinders are bright and clear.
Distortion An optical effect in some lenses where straight lines come out slightly bowed. You often see ‘barrel distortion’ with wideangle lenses or ‘pincushion distortion’ with telephoto lenses at their longest zoom setting. More expensive lenses tend to have less distortion but, generally, the longer the lens’s zoom range the more likely you are to see distortion creeping in.
Distortion correction Software correction carried out either in the camera during image processing or later on in software to correct bowed edges caused by lens distortion.
DNG Converter (Adobe) This is a handy free tool you can download from the Adobe website for converting digital camera RAW files into Adobe’s generic DNG format. It’s useful if you have a new camera but an older version of Photoshop, Elements or Lightroom that won’t open its RAW files.
Dodge and burn Dodging and burning is an old black and white technique for darkening or lightening different areas of a print while it's being developed. It is a creative technique that's just as relevant with digital images. It's done to enhance the tones, the composition and the balance of a picture to create a visually satisfying image.
Drive mode This controls what happens when you press the shutter release. In regular single-shot mode the camera takes a single photo. In continuous mode, it keeps taking pictures for as long as you hold down the shutter button. You’ll also find a self-timer mode and other options.
Drone Any remote control flying craft that can carry a camera. The drones available to the public are helicopter-style ‘multi-rotor’ devices – typically ‘quadcopters’ rather than the aircraft used by the military. The rotors are controlled by a central computer for easier flight controls.
Some lenses have very large or protruding front elements that make it impossible or impractical to use regular filters or filter systems. Instead, they may offer a slot towards the rear of the lens for inserting drop in filters, though the types available and what you can do with them are much more limited that regular filter systems.
DSLR This is an interchangeable lens camera where you see an optical image in the viewfinder showing what the lens sees. They do this using a mirror inside the body that reflects the image seen by the lens up into the viewfinder. When you take a picture, the mirror flips up out of the way so that the image passes through the body to the sensor at the back of the camera. DSLRs work in the same way as SLR (single lens reflex) film cameras, but substitute a digital sensor for the film.
Dual image stabilization A system that uses both in-body image stabilization and optically stabilized lenses to produce an even stronger stabilizing effect.
Dust Off (Nikon) A system offered with Nikon DSLRs for dealing with dust spots on the sensor. You take a reference shot of a white card which highlights any dust spots, and then Nikon image-editing software can use this to target dust spots on your photos and process them out.
DX format (Nikon) This is Nikon’s name for its APS-C format DSLRs. Some Nikon lenses are designed specifically for these smaller format models, and they include ‘DX’ in the lens name to signify that the can’t be used on the full frame models (well, they can, but only in a ‘DX crop’ mode).
DxO Paris-based software company famous for its optical research, testing systems and software. It publishes DxO PhotoLab (previously known as DxO Optics Pro), FilmPack and ViewPoint, and has recently acquired the Nik Collection from Google.
Dynamic Area AF (Nikon) A focus mode used on Nikon cameras for use in continuous shooting mode. You follow the subject using a group of autofocus points working in unison to track and maintain focus more intelligently and with a wider margin of error than a single focus point.
Dynamic range This is the brightness range the camera can capture before starting to lose detail in bright areas (like the sky) and dense, dark shadows. Generally, the larger the camera’s sensor, the better its dynamic range. RAW files capture a slightly wider dynamic range than JPEGs.
Dynamic range expansion A feature on some cameras which expands the range of tones the sensor can capture. It works by reducing the exposure to be sure of capturing extended highlight detail, then modifying the tone curve to restore midtone brightness.
E-mount (Sony) This is the name of the lens mount used by Sony mirrorless cameras. Regular E-mount lenses fit its APS-C format cameras, like the Sony A6500, while FE lenses fit its full-frame mirrorless cameras, including the A7 series and Sony A9. Sony also makes A-mount lenses for its Alpha SLT cameras, but these are not the same.
Effective focal length The angle of view of a lens changes according to the size of the sensor in the camera. A smaller sensor captures a narrower angle of view and makes it look as if the lens has a longer focal length. So in addition to the actual focal length, the manufacturers will usually quote the 'effective' focal length too.
Effective pixels Camera makers quote two megapixel figures. The bigger, 'gross' figure counts all the photosites on the sensor, but many of those around the edges are used for calibration and other technical purposes, so makers also quote the 'effective' pixels, which are the ones actually used to make the image. This is the important figure.
Effects Any image adjustment that produces a ‘look’ characteristic of specific photographic or darkroom techniques. It can include infra-red effects, as created by infra-red film, a ‘polarising’ effect to simulate the results from using a polarising filter on the lens, a ‘tilt-shift’ effect to replicate the shallow depth of field of an extreme close-up and so on. Effects can sometimes be applied in-camera but are more likely to be added in software.
Effects (in-camera) Many cameras offer a range of special image effects, usually taking over some or all of the camera controls and using in-camera image processing too. Examples include vintage sepia toning, tilt-shift 'miniature' effects, toy camera or cross-processing effects.
Electromagnetic diaphragm A system introduced by Nikon for some of its lenses where the lens aperture diaphragm in the lens is controlled electromagnetically rather than by the traditional mechanical linking. This gives more accurate and consistent exposures, especially during continuous shooting, where the lens diaphragm may be adjusted many times a second.
Electronic rangefinder A feature which uses the camera’s autofocus mechanism to confirm focus even when you’re using manual focus mode. You turn the focus ring and the AF point lights up when the subject below it comes into focus. It can be useful when it’s hard to judge sharp focus by eye.
Electronic shutter Some cameras now offer electronic shutters which start and stop the exposure digitally rather than with a mechanical shutter. These are silent and can offer very high shutter speeds, though most use a ‘scanning’ process which makes them unsuitable for action photography because while the exposure time for any particular strip of the sensor is very short, the length of time taken to scan the full sensor area creates distortion and 'rolling shutter' effects with fast-moving subjects.
Electronic viewfinder (EVF) Essentially, this is a tiny LCD display seen through a magnifying eyepiece. They’re used on some bridge cameras and high-end compact cameras, and on many mirrorless cameras. They replace the optical viewing system you get with a DSLR.
Element (lens) Camera lenses are made up of not just one single lens but many different lens 'elements', sometimes cemented or fixed together in 'groups'. A comparatively simple prime (non zoom) lens may have 6-7 elements while a complex zoom lens might have 17 or more. The different lens elements are needed to compensate for a variety of common lens aberrations and offer autofocus and zoom capabilities.
Elements (Photoshop) (Adobe) Cut-down version of Adobe Photoshop designed for novices and enthusiasts. It comes with a handy Organizer app for managing your photos, but a lower-powered version of Adobe Camera Raw. You pay outright rather than via subscription.
EV compensation Used to adjust the camera’s automatic exposure setting to make the picture come out lighter or darker. Camera meters aren’t foolproof and sometimes you do need to make adjustments. Doing it this way is quicker than swapping to full manual control.
EXIF data Date, time and shooting information embedded invisibly in digital photos by the camera. It includes the shutter speed, lens aperture, ISO setting and more. EXIF data is useful later on if you want to see how certain pictures were shot or search for photos based on their settings.
Expeed (Nikon) Nikon’s own brand name for the image processors used in its digital cameras. More powerful processors are needed for higher-resolution sensors and faster continuous shooting speeds, and play a part in noise reduction at high ISOs and image quality generally.
Export More and more photo editing applications now work non-destructively, so that the editing changes you make are stored alongside the image in a metadata file or within the software's image browser, and are not applied directly to the image. To produce a photo with your changes 'baked in', you have to export a finished version of the image.
Exposure Exposure is the science (and the art) of making sure the sensor gets exactly the right quantity of light to produce a good image. Exposure is adjusted using shutter speed (the length of the exposure), lens aperture (how much light is passed through) and ISO (the sensitivity setting of the camera). Camera's have light meters to estimate the correct exposure setting but it's sometimes necessary to override this with manual adjustments.
Exposure latitude A term used to describe a film's tolerance to overexposure and underexposure and its ability to capture tones in the brightest and darkest parts of a scene, even in high-contrast lighting. The modern-day equivalent with digital sensors is dynamic range, though sensors rarely approach the dynamic range (exposure latitude) of film.
Exposure mode This controls the camera's operation, from fully-automatic (the camera controls everything), semi-automatic (you can choose the shutter speed or lens aperture) to manual (you choose all the settings).
Exposure preview Some cameras can simulate the effect of exposure adjustments on the LCD screen or electronic viewfinder (this is not possible with an optical viewfinder), making the image lighter or darker as you adjust the exposure. It’s not a precise guide to exposure but it can be useful.
Exposure steps/increments Digital cameras offer finer exposure adjustments than whole stops (EV) values. By default, they offer 1/3EV adjustments to the shutter speed, lens aperture and ISO setting – though some cameras offer 1/2EV adjustments as an alternative, in line with older film cameras.
Exposure value (EV) A numerical value given to the amount of light in a scene. For example, bright sunlight might produce an EV of 17. In practice, cameras deal only in shutter speeds and lens apertures and you're only likely to see EV values on handheld light meters.
Exposure X (Exposure Software) Exposure recreates the look of old films and processes. It works both as a plug in and as a standalone application, and in this version it adds browsing tools and non-destructive editing. Adjustments are stored alongside photos rather than being applied directly.
External editor Image-editing software can’t always do everything you need to an image, so most have the ability to use ‘external editors’ – they send the file to another program, where you make the changes you want to make, and then the edited version is sent back to your original software for any further work. This is how plug-ins work too, but the difference is that external editors are full-blown standalone programs. Only a few programs, such as Lightroom and Capture One Pro, support external editors.
External flash A flashgun designed to clip to the top of the camera on its accessory shoe or to be used off-camera and fired remotely by cable, radio control or infra-red. External flashguns have more power than the camera’s built-in flash and a lot more flexibility in the way you can control and direct the light.
Eyepiece shutter A tiny blind in the viewfinder eyepiece that stops light entering and upsetting the exposure (normally the eyepiece is covered by your eye). It can be useful for long exposures or other shots where you’ve stepped away from the camera. Some cameras come with a small viewfinder cap fixed to the shoulder strap.
F-Log (Fujifilm) Extended dynamic range movie mode introduced by Fujifilm to handle high-contrast lighting, extending dynamic range by 200% or 400%. Other higher-end movie cameras have a similar feature. It produces flat-looking footage but with extended data in the shadow and highlight areas and the idea is that you process the video later on a computer (grading) to achieve the finished look. It's the video maker's equivalent of shooting RAW files.
Face detection Some autofocus systems identify human faces within a scene and then adjust the focus and exposure for that face. It’s popular on compact cameras and is used on some DSLRs and mirrorless cameras too.
Feathering A way of softening the edges of a selection or mask so that there’s no obvious boundary between the adjusted area, or a selected object, and the rest of the picture. Feather values are usually quoted in pixels.
Film ‘Analog’ film comes in three main types: colour transparency (slide) film, colour negative and black and white negative. It also comes in many sizes, from 35mm through medium format roll film to large format sheet film. Smaller formats than 35mm are still available, such as 110 and 126, but are less popular now.
FilmPack (DxO) Software that replicates the look of old films and darkroom processes together with ageing effects like scratches and light leaks. It can work as a standalone application and as a plug-in (Elite edition). It also integrates with DxO Optics Pro, DxO's RAW conversion/correction tool.
Film simulation Image settings on some cameras which attempt to recreate the colours and tonal quality of classic films. Fuji offers Velvia, Provia and Astia film simulations to replicate its films of the same name. You can choose these in-camera if you shoot JPEGs, or apply them later to RAW files.
This is a calculation used to work out the effect of different filters on the exposure needed, but it's largely fallen out of use with the arrival of digital cameras and especially mirrorless cameras. For example, a red filter, a contrast filter used in black and white photography, might have a filter factor of 3, so that you would measure the exposure without the filter attached, put on the filter and then increase the exposure by 3 stops. to compensate for the filter.
This is a mounting system for filters which attaches to the front of the camera lens via its filter thread and has slots for inserting two or more filters. Often there will be a slot closest to the camera lens for inserting a dedicated polarizing filter which can be rotated independently of the rest. The other slots accept square filters such as graduated filters or neutral density filters like the Lee Big Stopper.
The word 'filters' in photography can have several meanings. Traditionally, a filter is an optical attachment for a lens that modifies the light entering the camera. These come in various types and include traditional round filters that screw directly to the filter thread on the lens, and square filter systems that use a filter holder and square filters that slide into slots in the holder.
Filter system Most filters these days are designed as modular filter systems consisting of a square filter holder with slots for three rectangular filters and, sometimes, a circular polarising filter too. The filter holder attaches to the camera lens via an adaptor ring. In this way, the same filter holder and filters can be used with many different lenses.
This is a fine screw thread cut into the front of almost all DSLR and mirrorless camera lenses. This is where you screw in round filters, or the adaptor rings for square filter holders. The size of the filter thread varies, so you need to make sure you buy filters or adaptors the right size for your lens.
Firmware Programmable hardware inside the camera (somewhere between hardware and software) that handles the camera's controls, functions and features. Camera makers sometimes release firmware updates to fix bugs or add new features.
Fisheye lens A fisheye is an ultra-wideangle lens that no longer attempts to render straight lines as straight and instead produces images with strongly curved edges and a characteristically surreal look. It's a striking effect, though one to be used occasionally.
Flange distance This is the distance between the mounting plate on a camera that takes interchangeable lenses and the sensor itself. Mirrorless cameras have a shorter flange distance because there's no mirror inside the body, and this makes the cameras slimmer. DSLRs have a longer flange distance because there needs to be space inside the body for the mirror that this design gets its name from. This makes DSLR bodies thicker. This difference in flange distances means that it's sometimes possible to use lens adaptors to fit lenses of a different type, brand or lens mount to a camera. This generally works one way only – you can mount a lens with a longer flange distance (e.g. a DSLR or old film SLR lens) on a camera with a shorter flange distance (e.g. a mirrorless camera) but not the other way round.
Flash Flash is the most popular artificial light source for both amateur photographers and professionals. It delivers a short, intense burst of light that can freeze moving subjects and illuminate objects up to a few metres away. Many cameras come with a built-in flash, but it's also possible to add a more powerful and versatile external flash units to more advanced cameras. Flash is a complex area that gets a lot more interesting and a lot more complicated when you start using it for creative multi-light setups.
Flash compensation Flash power is normally handled automatically by the camera, but you can increase or reduce the flash power with the flash compensation option – it’s just like using the exposure compensation option with automatic exposure.
Flash output (manual) Flash power is usually handled automatically by in-built flashguns and external flashguns. The exception is studio flash, where you adjust the power manually in fractions of full power. 1/1 is full power, 1/2 is half power, 1/4 is quarter power and so on. Some smaller flashguns offer manual power settings too.
Flash sync speed Digital SLRs and compact system cameras use focal plane shutters and these have a design limitation – there is a maximum speed at which the whole sensor is exposed at once. This is the maximum flash synchronisation speed. Beyond this, the sensor is exposed in a moving strip, which is no good for flash.
Flexible Program (Nikon) Nikon’s name for its ‘program shift’ control, where you can change the balance of lens aperture and shutter speed without having to leave the program AE mode – you simply turn the command dial until the camera displays the lens aperture or shutter speed you want.
Fn (function) button One or more buttons on more advanced cameras which can be used for quick access to useful settings such as picture style, white balance, ISO setting or more. They will have default settings already which you may find useful, so you don't have to change them.
Focal length This tells you a lens’s magnification or angle of view (it’s the same thing really) and it’s quoted in millimetres. Sometimes the makers quote actual millimetres and sometimes they quote the ‘effective’ focal length, which is what the lens would be equivalent to if it was a 35mm camera.
Focal plane mark A small marking on the top plate of some cameras which indicates the position of the focal plane – the sensor surface – inside the camera. You’re unlikely to need this unless you are using manual macro photography setups based on precise focus and magnification values.
Focal plane shutter The type of shutter used by interchangeable lens cameras (ILCs) such as DSLRs and compact system cameras. The shutter is mounted directly in front of the sensor (at the focal plane) and shutter ‘curtains’ open to start the exposure and close to end it.
Focus limiter A switch found on some telephoto and macro lenses to restrict the autofocus to a specific range. This speeds up the autofocus for situations where you know you won't need the lens's full focus range.
Focus mode Camera autofocus systems work in one of three modes: single-shot autofocus (usually abbreviated to 'S'), continuous autofocus ('C') and manual focus ('M'). If you're taking one photo at a time, use single-shot autofocus – the camera will focus once and then fire. If you're using continuous shooting mode, use continuous autofocus – the camera will keep refocusing all the time the shutter button is held down.
Focus peaking A special display mode designed to help with manual focusing when using an LCD display or electronic viewfinder. It exaggerates the edges of objects when they come into focus and can give a much more visible focus ‘snap’ than the regular display.
Focus point Autofocus systems can focus at different points around the frame – the more advanced the autofocus system, the greater the number of AF points. You can either leave the camera to choose the autofocus point with 'auto AF' mode (or 'auto area AF') or select it yourself with single-point AF mode. Some cameras offer face-detection or subject-tracking AF options.
Focus stacking A hardware and software technique for getting more depth of field in close-up and macro shots. You take a series of images at slightly different focus settings, then use focus stacking software to blend together the sharpest areas of each into a single image.
Force flash A mode where the flash is made to fire whether the light is low or not. Normally, the camera won’t fire the flash in bright light, but forced flash mode overrides this. Flash can be useful for fill-in light for portraits, even in daylight, and especially if your subject’s face is in shadow.
Format (memory card) Completely wiping a memory card so that you’re starting again with a clean slate, so to speak. It’s not essential if you only ever use one camera, but if you use the same card in more than one it will clear up unwanted files and folders left behind by other cameras.
Foveon sensor (Sigma) Sigma's Foveon sensor uses a unique layered design to capture blue, green and red light on separate layers. It mimics the multi-layer construction of colour film.
FPS (frames per second) In stills photography, this is the camera's maximum continuous shooting speed – the number of frames it can capture per second. In video, this is the number of frames of video per second, typically 30fps, though sometimes 25fps or 24fps.
Frames/borders Another word for borders applied digitally to a photo, either as a compositional aid to enclose the picture, for example a black keyline, to simulate the look of negatives or prints, or (in the worst case) to produce a pretend wood or metal frame.
Friction control (tripod) Tripod heads often have a friction control for resistance, which prevents camera damage and allows precise positioning. This is commonly found on ball and video heads.
Fujifilm Camera, lens (and film) maker now specialising in high-end enthusiast and professional equipment such as the X-T2 mirrorless interchangeble lens camera, X100F high-end compact camera and GFX medium-format mirrorless camera.
Full frame sensor This is a sensor the same size as the 35mm film negative, measuring 36 x 24mm. This is the most desirable camera type for most enthusiasts and pros, but full frame cameras are bigger, heavier and more expensive. Most DSLRs and mirrorless cameras use smaller APS-C sensors.
Full HD Video with a resolution of 1920 x 1080 pixels. It’s sometimes abbreviated to ‘1080 video’.
FX format (Nikon) This is Nikon’s name for its full frame DSLRs, to distinguish them from its APS-C size ‘DX’ models. Most Nikon lenses are designed to fit this larger FX format. Those that don’t have ‘DX’ in the model name – though they can still be used on an FX Nikon in ‘DX crop’ mode.
Gain (audio) Gain is a term you're likely to meet in video rather than stills photography. It basically means turning up the input signal strength to record a decent value. Videographers are more likely to talk about increasing the ISO setting rather than the 'gain', though it amounts to the same thing. It's still used for audio recording, where your camera or sound recorder will probably have a 'gain control' or some kind of 'AGC' – automatic gain control.
Geared column A geared column is a tripod centre column where the height can be adjusted by a flip-out handle – you turn the handle to wind the column up and down. This is slower than a regular centre column, but much more precise, and useful for architectural or still life photography, where the camera position often needs very small, fine adjustments.
With a regular centre column you simply loosen a clamp and slide the column up and down. It's fast, and better suited to most photographic needs, but it's also less precise.
Geared head A geared head is a special type of tripod head designed for very fine adjustments applied with handles or knobs that move the head via fine gears. With some models, you can disengage the gears for rough positioning, then re-engage them for fine tuning.
A geared head is unnecessary for most kinds of photography but can be useful when very fine positioning is needed, for example with still life or macro shots.
Ghosting (HDR) When you merge a series of different exposures to create a single HDR image, you sometimes get movement between the frames from leaves blowign in the breeze, waves, pedestrians and moving vehicles, and these can cause 'ghosting' in the merged image. Most HDR software has a 'ghost removal' option which slows down the merging process but can reduce or remove this ghosting.
Gigabytes (GB) A unit of storage used both for computer hard disks (and SSDs) and for memory cards. 1GB is approximately 1,000 megabytes.
Global shutter An advanced kind of electronic shutter that can capture the entire image area at once, instead of scanning it strip by strip. This should eliminate the rolling shutter effect usually associated with electronic shutters and make them much more effective for capturing moving subjects. It does, however, require advanced sensor technology, especially in larger sensor sizes, and powerful image processing, which is why it's still in its infancy in the mass market.
Golden hour In photography, this is the hour after sunrise or the hour before sunset, where the sun is low in the sky and casts an attractive, warm light that makes landscapes look more appealing. Sometimes it's possible to replicate this effect in software – MacPhun Luminar has a 'Golden Hour' filter.
Google Drive Online cloud storage system offered by Google as part of its Gmail, Google Photos, Google Docs system and more. You get a small amount of Google Drive storage with your free account, but you will need to pay a subscription for more storage space. It's an alternative to Dropbox.
Google Photos A free photo storage and sharing tool that's part of your Google account. You can store, sort and search all your photos online and they're automatically available in your smart devices too, via a Google Photos app. It's not designed for professional use, but it does use machine learning, or artificial intelligence, to identify your photos automatically, saving lots of manual keywording and tagging.
GoPro One of the best known brands of action camera. GoPro has made its name through the activities of high-profile adventure sports personalities and even TV production companies. The cameras are small, square and tough and at the centre of a large range of camera mounts, supports, gimbals and other accessories.
GoPro mount A mounting system first developed by GoPro but now used widely by other action camera and accessory makers. In theory, any GoPro mount compatible item should be compatible with any other.
GPS GPS receivers use global positioning satellites to fix the camera’s location and embed this in the photo’s metadata. You can look this up later and many programs can show the location the photo was taken on a map. Only a few cameras have GPS built in, but it’s standard on smartphones.
Gradient Map A type of adjustment layer that translates the different brightness levels in a photo on to points on a gradient. It's an effect you wouldn't necessarily use that often, though you can effectively convert a colour image to black and white using a black-white gradient map, for example.
Gradient mask An image mask that transitions from clear to opaque gradually using a soft gradient. It could be used to darken a bright sky in a landscape shot, for example, without producing a hard edge where the adjustment takes effect.
Grading The video equivalent of the image-enhancement stills photographers carry out on their images. Videographers 'grade' video to match the colours and exposures between clips, to create a certain 'look' or to edit video shot in a 'log' mode for extra dynamic range.
Graduated filter Graduated filters are clear at the bottom but darkened at the top, with a smooth, graduated blend in between. You use them in landscape photography to tone down bright skies without affecting the land. You can also create graduated filters 'digitally' in image-editing software.
Grain Film grain is caused by the random clumping of silver halide grains (black and white) or dye clouds (colour film) – the individual grains or colour spots are too small to see. Film grain looks very different to digital noise – many photographers use film grain simulation filters and tools.
Gray card Used for accurate white balance calibration, usually under artificial lighting where the colour of the light sources is unknown or variable. You can use the camera’s manual white balance preset control to take reading from the grey card, or set the white balance using the card and the WB eyedropper tool in many image-editing programs.
Grip Also known as battery grips, these are accessories that attach to the bottom of some DSLRs or mirrorless cameras to offer extended battery life and, usually, a duplicate set of controls to make the camera suitable for extended use in portrait (vertical) mode. In some cases, a battery grip may also increase the continuous shooting speed of the camera. For example, the battery grip of the Nikon D850 increases its continuous shooting speed from 7fps to 9fps.
Group (lens) Camera lenses used complex configurations of different optical elements, often cemented or fixed together in 'groups'. Lens groups may be designed to counteract common optical aberrations and you may have autofocus 'groups' and zoom groups. Lens elements and groups often move relative to each other in complex ways as the focus and zoom settings are changed.
Guide number (GN) A measure of the power of a flashgun, whether it’s a built in flash or an external flashgun. You take the guide number and divide it by the subject distance in metres to get the lens aperture you should use. Flash power is usually controlled automatically these days, though, so the guide number is just an indication of the maximum power.
Handheld photography Any photography – obviously – where you’re holding the camera with your hands rather than using a tripod or some other form of camera support. It has special implications for night and low light photography where it’s important to use shutter speeds fast enough to prevent camera shake.
HDMI Standard digital interface for connecting video and display equipment. Cameras have HDMI ports for direct connection to TVs, for example, but more advanced models can also connect to external monitors for video recording, or external video recorders.
HDR (high dynamic range) HDR stands for high dynamic range photography. It combines a series of frames taken at different exposures to capture a much wider dynamic (brightness) range than the camera could capture with a single exposure. These exposures are merged using HDR software.
HDR Efex (Nik Collection) Software plug-in for creating HDR (high dynamic range) effects from single images or bracketing sets of exposures. It's part of the Google Nik Collection. You can apply preset HDR styles with a single click or adjust and make your own effects using extensive manual controls.
HD video ‘HD’ stands for ‘high definition’ to distinguish it from older, lower resolution video standards. HD actually comes in two formats: standard HD has a resolution of 1280 x 720 pixels, full HD is 1920 x 1080 pixels. Both use the same 16:9 aspect ratio.
Headphone socket All DSLRs or compact system cameras which shoot video will have an external microphone socket for better sound quality – but for pro videographers it’s just as important to have a headphone socket for monitoring sound levels while shooting. You only get this on more advanced models.
Healing A process or set of tools for removing an object from a picture or repairing a blemish simply by painting over it. It's like cloning, except that you don't have to define a nearby clone 'source' to use for the repair – the healing tool chooses and matches pixels automatically.
High key A photo where the tones are predominantly bright or white. It's partly the subject that makes a photographer high key - a white cat on a white cushion, for example, and partly the exposure technique - slight overexposure will give a high key look.
Highlight recovery When you shoot RAW files there is often a little extra highlight detail in the data than is initially visible, and a good RAW converter will be able to recover this detail to correct any 'blown out' areas. There's no much margin for correction, however – typically you might be able to recover 1EV of additional highlight detail, but rarely more.
Highlights The lightest tones in a picture. It’s a pretty vague definition, but most photographers take it to mean tones which are at or near a full, featureless white. Retaining or recovering highlight detail – in bright skies, for example – is a big priority for keen photographers.
High speed sync High-speed sync is a flash mode that counters limited flash synchronisation speeds of focal plane shutters by pulsing the flash several times, potentially impacting flash power. Elinchrom's 'High Sync' reduces this power loss.
Histogram A graphical display of the brightness values in the picture. The darkest tones are at the left and the brightest on the right, and the vertical bars show the number of pixels for each brightness value. Histograms are an invaluable exposure aid when taking pictures, and when editing them later.
History Many programs can store a 'history' of all the editing changes you've made since you opened an image. Using this you can check what you've done and even backtrack to an earlier image state if you realise you've made a mistake. Some programs can store the history as part of the saved image file, while non-destructive editors like Lightroom will store it indefinitely as part of the image's adjustment metadata.
Honeycomb grid A honeycomb grid is a lighting attachment designed to narrow the light from a flash or continuous lighting source into a tight beam. It gets its name from the hexagonal shape of the holes in the grid. Where other lighting attachments are designed to spread and soften the light, a honeycomb grid is design to focus it tightly on a single area. It's a type of light modifier.
Hotshoe Accessory shoe on the top of more advanced cameras that’s designed for sliding in an external flashgun, though these days it may also be used for electronic viewfinders, wireless remote control units and more.
Hue/saturation A way of adjusting the colours in an image – the Hue adjustment shifts the colour along a continuous spectrum, while the Saturation adjustment changes its intensity. For example, you can shift the hue of leaves away from yellow towards blue and increase their saturation to make the leaves look ‘fresher'.
Hybrid autofocus Autofocus system that combines contrast autofocus and phase detection autofocus. It works using special phase-detection sensors built into the sensor. Contrast AF is typically slow but accurate, while phase detection AF is typically fast if potentially less accurate.
IBIS (in body image stabilisation) Short for 'in-body image stabilisation' and a term used by Fujifilm for its X-H1 pro mirrorless camera. In-body image stabilisers shift the camera sensor to counteract any camera movement during the exposure. It's the first time Fujifilm has used in-body stabilisation, but it's already used by Pentax, Panasonic, Sony and Olympus.
iCloud Apple's cloud-based storage service, integrated into its desktop and iOS (iPhone and iPad) operating systems. You can use it to make your photos available on all your devices via iCloud Photos and the Photos app, though as with other cloud services, once you've used up your initial free allocation, further storage has to be paid for on a subscription basis.
ILC (interchangeable lens camera) Any camera where you can change lenses. Once, this was just DSLRs, but now mirrorless cameras are included in this category and, for the sake of argument, Leica’s ‘rangefinder’ cameras should be included too. ILC is not a widely used term but it is the most correct description.
Image circle All lenses produce a circular image on the camera sensor or film, and this 'image circle' must be at least large enough to cover the full film/sensor area. Different lenses designed for different sensor sizes and formats have different-sized image circles. Lenses designed for APS-C format cameras, for example, have a smaller image circle than lenses for full frame cameras. Some specialised perspective control or tilt-shift lenses have larger image circles to allow for lens movements relative to the camera.
Image editor Any program which can edit, enhance or manipulate digital images is technically an image editor, though usually this term is reserved for more advanced, technical programs like Photoshop rather than simpler everyday photo management tools like Apple Photos or Google Photos.
Image stabilizer A mechanism that counteracts camera movement during the exposure. Lens-based stabilisers use a moving lens element, while sensor-based stabilisers move the sensor itself. Image stabilisers are used to get sharper telephoto shots and low-light shots without camera shake.
Import With some programs you can't just open an image straight away, you have to import it into the software's catalog first. This is how database-driven cataloguing programs like Lightroom, Capture One and Aperture work.
Infra red A branch of photography that uses parts of the light spectrum not normally visible to the naked eye but which can still be captured on film or digitally using black and white or colour film made sensitive to infra red or a digital camera modified to remove the infra red filter that normally covers the sensor.
Inpainting (Serif) An automatic object removal tool in Serif Affinity Photo. You brush over the object or blemish that you want to remove and the Inpainting Brush automatically fills in the area with pixels and patterns from surrounding regions. It's quick and often very effective and comparable to Adobe's 'content aware' retouching tools.
Interpolation Using mathematical analysis to fill in the gaps in data. The photosites on sensors only capture red, green or blue light, so interpolation is used to examine surrounding pixels and calculate full colour values from those. When you increase the size (in pixels) of a photo, the software interpolates new pixels from the existing ones.
Intervalometer A camera setting or remote controller which fires the camera’s shutter at set intervals, stopping when it’s taken a specified number of images. The pictures can then be used to analyse movement or change over time or, more likely, combined to make a time lapse movie.
Interval timer Sometimes called an 'intervalometer', this is a feature on more advanced cameras that takes picture at fixed intervals automatically. It’s most often used for time lapse photography. You set the interval between pictures and the number of shots you want the camera to take.
ISO This setting increases the camera sensor’s sensitivity to light. Each ISO step doubles the sensitivity, so it’s easy to use ISO as another exposure control alongside shutter speed and lens aperture. The more you increase the ISO, though, the more the image quality degrades.
ISO expansion This setting increases the camera sensor’s sensitivity to light. Each ISO step doubles the sensitivity, so it’s easy to use ISO as another exposure control alongside shutter speed and lens aperture. The more you increase the ISO, though, the more the image quality degrades.
JPEG This is a standardised, universal file format for digital photos that can be displayed by practically any device without any kind of conversion. It uses powerful compression to reduce the file size of digital photos so that you can get more on to a memory card or a hard disk, and they’re quicker to transfer. There can be some loss of quality (often invisible to the naked eye), so for ultimate quality many photographers shoot photos in their camera’s RAW format instead. It’s only more advanced cameras that offer this RAW option, and it produces much larger files which you will need to process yourself later on.
Keystoning Where the tops of tall buildings appear to converge. This happens when you're so close you have to tilt the camera upwards to get everything in. You can correct it by choosing a more distant viewpoint and keeping the camera level, or by using keystone correction tools in software.
Kit lens A relatively inexpensive general purpose lens sold with a camera body as a kit. Buying both at the same time is much cheaper than buying them individually. Most DSLRs and mirrorless cameras are also sold ‘body only’ for those who already have lenses.
Lasso tool A simple selection tool where you drag an outline around the object or area you want to select. The selection is 'closed' and ready for use when you finish the loop back at the point where you started. The Lasso tool is not very accurate but when used in conjunction with other selection tools and editing processes it can nevertheless be very effective.
Lavalier (lav) mic This is a small microphone designed to attach to a speaker's clothing for interviews or presentations, for example. They're usually small and unobtrusive, they're hands-free and they help exclude other background noises. They may also be called lapel mics. Some are connected to the camera or sound recorder by wire, others work wirelessly.
Layers Best thought of as a series of transparent overlays you can place over an image to add other images, text, effects or adjustments. You can also use masks to hide or show different parts of each layer and control the areas they affect.
LCD display The key specs here are the size, measured across the diagonal, and the resolution, measured in thousands of dots. For example, you might get a 3-inch LCD with 921k (921,000) dots.
LED lighting New type of ‘continuous lighting’ that uses relatively little power but still provides enough light for video, still lives or portrait shots. Small LED panels can clip to a camera’s hotshoe, larger ones have their own stands and control panels.
Lens The lens is a fundamental part of any camera. It's what creates the image on the camera sensor (or film). Some cameras have a fixed, non-removable lens while others offer interchangeable lenses. Your choice of lens has a major impact on the appearance of your pictures, including the lens's focal length (angle of view) and its aperture setting (which you may or may not be able to adjust). At a simple level the lens is just the thing on the front of the camera, but on a more advanced level lenses open up a whole world of photographic choices, buying decisions and technical comparisons.
Lens adapter In principle, you can't mix and match different types and brands of lenses with different camera bodies. Each camera maker uses its own bespoke lens mount and different mechanical and electronic connections between the camera body and lens. However, it's often possible to make lenses fit different brands and types of bodies with lens adaptors. These are usually from third-party makers and designed for users who don't mind a few compromises in camera functions. For example, you may lose autofocus functions and have to use manual focus only, and it's likely that you'll have to use manual exposure and lens aperture control rather than the camera's full range of exposure controls.
Lens corrections Lenses aren't perfect – they all have optical aberrations of one sort or another. Now, though, many software applications have lens correction to correct these digitally, either with manual controls or automatic lens correction profiles.
Lens hood Lens hoods can reduce lens flare and improve contrast when there's a bright light source just outside the edge of the frame, but they won't help if the sun, for example, is in the frame. Lens hoods are usually 'petal' types that allow for the fact the image frame is rectangular.
Lens modulation optimiser (LMO) A processing algorithm used by Fuji in some of its cameras to counteract the softening effects of diffraction at small lens apertures, and image softness at the edge of the frame. It seems likely the LMO is simply applying some intelligent sharpening.
Lens mount This is the physical connection between a lens and the body of a DSLR or mirrorless camera. It consists of a twist-lock bayonet mount and electrical connectors. The lens mount is specific to a camera brand – you have to make sure you get lenses in the right fitting for your camera.
Lens profile Almost all lenses suffer from aberrations, including distortion, chromatic aberration and vignetting. These are difficult to eliminate optically in the lens design, so software publishers are increasingly offering lens correction profiles to do this digitally. The software can identify the lens used from the image’s EXIF data and then find and apply the correct profile automatically.
Levels A basic image adjustment found in most image-editing applications. You can use Levels to inspect the image histogram and move the black point and white point sliders so that there's a full range of tones from solid black to brilliant white.
Light leak Old and cheap film cameras have poor seals and badly-fitting backs that may let light through on to the film inside. This produces pale streaks across the image or at the edges and has become associated with an ‘old camera’ look. Some programs now replicate light leaks digitally in a variety of colours, patterns and orientations.
Light meter A device for measuring light levels. Digital cameras come with their own sophisticated internal light meters, but it is possible to get external light meters where the settings have to be transferred to the camera manually. This is slower, but has advantages in some circumstances.
Lightroom (Adobe) All-in-one photo cataloguing, organising and editing tool that also synchronised with a mobile app so that you can browse and share your images while you’re on the move. It uses the same RAW conversion engine and tools as Adobe Camera Raw, which comes with Photoshop.
Lightroom Classic (Adobe) Lightroom is an all-in-one photo cataloging, organizing and editing tool that also synchronizes with a mobile app so that you can browse and share your images while you’re on the move. It uses the same RAW conversion engine and tools as Adobe Camera Raw, which comes with Photoshop, but comes in two versions: Lightroom Classic CC uses the same desktop-based storage system and tools as the 'old' Lightroom, while Lightroom CC is a new stripped-down version with a simpler interface which uses paid-for cloud storage.
Lightroom Mobile An app for iOS or Android devices which works alongside the desktop Lightroom app to display images you've synchronised via Creative Cloud. When sync a Collection in the desktop app, that Collection and its images will appear in Lightroom Mobile. You can view and even edit images in Lightroom Mobile and your changes will be synchronised with the desktop version.
Liquify A Photoshop mode for bending, pinching and distorting areas of an image to create a special effect or 'improve' the body shape of a subject. Other applications offer similar tools.
Lithium ion Standard rechargeable battery type for digital cameras. Lithium ion batteries have good capacity, supply a constant output from fully charged until drained and have none of the ‘memory effects’ that affect other rechargeable battery types – you don’t have to wait until a lithium ion battery is flat before charging it again.
Live view Where the camera displays what the sensor is capturing either on the rear LCD or in an electronic viewfinder. All compact cameras and mirrorless cameras are effectively in ‘live view’ all the time. It’s only out of the ordinary on a DSLR, which has to go into a special mirror-up ‘live view’ mode.
Local adjustment Adjustments made only to specific areas in a photo, not the whole picture. You pick out the areas you want to adjust with selections, masks or brush tools.
Local contrast A relatively new type of image adjustment that splits a photo up into different areas, depending on its properties, and applies an optimum contrast adjustment to each. It’s used for a variety of ‘dehaze’ and similar tools. It’s also used as a kind of super-coarse sharpening which doesn’t make the edges of objects crisper in the normal way, but works over a much wider radius to give images more visual ‘punch’ from normal viewing distances.
Lomography Company which champions old, analog cameras, outdated or cross-processed film and relaunched classic lens designs. Lomography products are known for their expense, sometimes makeshift construction and general unpredictability, but also revered by their fans for these very reasons (well, probably not the expense), because they introduce the kind of randomness, unexpectedness and engagement lost in the transition to modern digital imaging.
Long exposure Long exposures turn moving subjects like water and clouds into an atmospheric blur. The exposure time often needs to be several seconds or longer, so a tripod is essential. In bright light you'll need a neutral density (ND) filter to get these long exposures.
Loupe In traditional film photography, this is a small magnifying eyepiece for examining the detail in a negative, slide or print. In digital imaging it's a magnifying view for use on-screen. Aperture and Capture One use a digital representation of a loupe, while Lightroom has a Loupe view where you can zoom in and out.
Low key A photo where most of the tones are dark, such as a black cat in a coal cellar. You can also give photos a low key look with slight underexposure. It gives photos a dramatic, moody look, though the subject matter has to be right for this to work properly.
Low pass filter A filter directly in front of most camera sensors to prevent interference (moiré) effects between any fine patterns and textures you photograph and the rectangular grid of photosites on the sensor. These filters actually blur fine detail slightly, and some makers no longer use them.
Luminance (contrast) noise The chief component in image noise and the one that's most difficult to remove because software can't easily distinguish between random image noise and real image detail. The result is that the more noise reduction you apply, the more you tend to lose fine image detail, resulting in images with obvious and objectionable ‘smoothing'.
Luminar (Skylum) Comparatively new image-editing software that offers instant effects presets made with a range of different filters and tools which you can combine and adjust manually. It offers easily-customised ‘workspaces’ which contain only the tools you need and which makes the interface as straightforward as possible.
LUT (lookup table) LUT stands for 'lookup table'. Essentially, it takes the colours in an image and remaps them on to new ones. It really is a table consisting of a large grid of colour swatches and how they should be adjusted in the converted images. Its closest equivalent is the device profiles used in colour management systems, which work on a similar principle, but LUTs are usually designed for creative effects rather than colour correction.
Macro lens Strictly speaking, macro photography where a real-life object is captured at the same size on the sensor. So a bee 10mm long would form an image 10mm long on the sensor. True macro photography needs dedicated 'macro' lenses.
Macro mode Many cameras and some telephoto lenses offer a 'macro' button or mode. This is rarely the same as true macro photography at 1:1 magnification. Instead, 'macro' is simply used as another word for close-up. This is the macro button on a Fuji X30 compact camera.
Traditionally, filters are attached by screwing them into the filter thread at the front on the lens. This applies both to round filters and to square filter systems, where the filter holder screws on to the lens via an adapter ring. Magnetic filter holders attempt to speed up the whole process using magnets rather than screw threads.
Managed files Image cataloguing programs store a database of images and their locations on your computer. Most will leave your image files where they are without moving them ('referenced' files) while others may offer to store your files within the image database (Aperture) as 'managed' files.
Manual exposure Where you set both the shutter speed and the lens aperture used by the camera. The camera’s exposure meter may recommend the settings, but you’re free to use or ignore this information. Manual exposure gives you total control but requires some experience.
Manual focus Useful when you want to make the most of depth of field – with often means focusing between two objects rather than on one or the other. It’s also handy for ‘zone focusing’ in shoot-from-the-hip style street photography, where you want an instant shutter response.
Mask Related to selections, but a more permanent way of masking out adjustments made to an image. For example, you might make an initial selection in an image-editor and then convert it into a layer mask which can be saved with the file and re-edited later if necessary.
Maximum aperture The maximum light-gathering power of a lens and a major selling point.It lets you use faster shutter speeds or lower ISO settings in poor light.This lens has a maximum aperture of 1:2.8. This is the same as f/2.8 – different makers use slightly different terminology.
Mechanical shutter The traditional form of camera shutter, a physical device which blocks light from the sensor until the moment you press the shutter release, then opens to expose the sensor for the required amount of time before it closes again. Mechanical shutters are either focal plane types, just in front of the sensor, or in-lens 'leaf' types.
Electronic shutters offer shorter shutter speeds on paper, but with current technology they're less effective at capturing fast-moving objects.
Medium format Professional cameras that use sensors larger than full frame. These fill the space previously occupied by 120 roll film cameras, though they are massively more expensive. ‘Medium format’ sounds like there should be a larger size still, but it harks back to the days of film when you could get large format 5x4” or 10x8” sheet film cameras.
Megapixels (MP) The number of pixels captured by the camera’s sensor. Smartphones typically have around 8 megapixels and upwards, while regular digital cameras typically have 16 megapixels or more. Megapixels used to be a good guide to image quality but now sensor size is more important.
Memory card Removable storage media used to store digital images in the camera. They come in different types (SD, Compact Flash, XQD, CFast), different capacities and speeds.
Memory card capacity This is measured in gigabytes (GB), and the larger the memory capacity the more photos and video clips you can store. It’s hard to give precise advice since cameras and user needs vary so much, but 16GB is a good starting point if you shoot RAW files as well as JPEGs, and consider 64GB-256GB if you want to shoot video, especially 4K.
Memory card speed Memory card makers quote the card’s maximum read/write speed in MB/sec, but it’s also important to know the minimum sustained speed for video recording. This is quoted using Class ratings (SD cards). Typically, you need Class 10 for 4K video as a minimum.
Merge (e.g. HDR) HDR (high dynamic range) images are usually created by blending a series of different exposures of the same scene to capture a wider brightness range than the camera could capture with a single exposure. These are then blended together by HDR software using a 'merge' process.
Metadata Any information embedded in a digital photo. It can include time, date and shooting information (EXIF data) embedded by the camera, keyword, caption and copyright (IPTC data) added by image cataloguing programs and, sometimes, image processing data added by non-destructive image-editing programs. See also: The ticking time-bomb of non-destructive editing.
Metering mode Digital cameras usually use multi-pattern/multi-segment light metering, but they also offer other 'metering modes' – centre-weighted metering (simpler) and spot metering (more precise). The camera will have a button or a menu option for changing the metering mode.
Micro Four Thirds (MFT) This is a sensor and lens format used by Olympus and Panasonic for their mirrorless camera ranges. The MFT sensor measures 17.3 x 13.0mm, so it's smaller than the APS-C sensors used in rival mirrorless cameras. This does have a modest effect on overall image quality, but the payback is the both MFT cameras and lenses are substantially smaller and lighter than rival APS-C models. The MFT format also has a slightly squarer 4:3 (four-thirds) aspect ratio, which some photographers might prefer.
Microlens (sensor) In order to maximise their light gathering power, each photosite on the camera sensor is covered by a tiny domed ‘microlens’ to capture and funnel in the light more effectively. Improvements to the microlens array can improve the sensor’s performance.
Microphone Any camera which shoots video will have a microphone built in, often stereo mics. For serious video work, though, an external microphone is needed. Some types plug into the camera’s hotshoe, others are used on the end of a boom or clipped to a presenter’s clothing (lapel mics).
Midtones Very broadly, the middle brightness tones in a photo. Imagine the full range of tones in an image split into four equal parts – the darkest quarter makes up the ‘shadows’, the lightest quarter makes up the ‘highlights’ and in between are the ‘midtones’.
Miniature effect Special effect provided in some cameras and image-editing programs which makes real-world scenes look like miniature models. It does this by blurring the top and bottom of the image to simulate the shallow depth of field of a close-up shot.
Mirrorless camera A relatively recent design that takes interchangeable lenses, just like a DSLR, but doesn’t use in internal mirror for its viewing system –if you take off the lens you see the sensor itself. Mirrorless cameras allow a shorter lens-to-sensor distance and full time live view.
Mirror up mode An option on more advanced DSLRs that flips the mirror up in advance of the exposure in order to give any vibrations from the mirror mechanism time to die down. It’s popular with fans of macro photography and some landscape photographers.
Mode dial Just about all digital cameras have these or an equivalent and you use it to set the exposure mode, such as full auto, program auto exposure, scene modes, movie mode and so on. More advanced cameras add PASM modes – Program AE, Aperture-priority, Shutter-priority and Manual.
Modelling lamp A continuous light built into many professional flashguns so that you can see the effect of the light ahead of taking the picture. Without a modelling lamp, you won't really be able to gauge the effect of the lighting without taking a shot and looking at the result.
Traditionally, modelling lamps were much lower-powered than the flash unit itself and not designed to provide illumination for taking pictures on their own. However, the increased use of video and its need for continuous lighting has mean that flash makers are now incorporating LED lamps which can be used for this kind of continuous lighting application.
Modifier (lighting) A lighting modifier is designed to change the character of the light from a flashgun, or some other source of artificial lighting. Mostly they soften or diffuse the light, or change its direction.
The most common type of lighting modifiers are the softboxes, brollies, honeycomb grids and other accessories attached to studio lighting systems. However, it's also possible to get lighting modifiers that attach to regular camera-mounted flashguns, providing a reflective surface for bounced flash or a mini-softbox for smoother and more even lighting.
Moiré A fine interference pattern sometimes visible when you photograph fine patterns. It happens when these clash with the rectangular grid of pixels on the camera sensor. Actually, you almost never see it – most cameras have anti-aliasing/low pass filters to prevent, and it doesn’t seem to be an issue for those that don’t.
Monitor calibration Monitors rarely display colours with complete accuracy, so some professionals use calibration kits that use a sensor to read the monitor’s colours and then apply a software profile to correct the display.
Monopod One-legged camera support that lacks the stability of a tripod (obviously) but offers invaluable support when using long, heavy telephoto lenses, and very popular amongst sports photographers for that reason.
Montage Two or more images combined, usually using layers in a program like Photoshop or Affinity Photo.
Mount adapter A lens mount adaptor which lets you mount a lens designed for one camera or brand on a different make or type of camera. For example, you can get adaptors for fitting DSLR lenses on some mirrorless cameras. Mount adaptors (lens adaptors) are used widely in videography.
MP4 MP4 is a video file format used by many digital cameras. It's simple to work with because it produces a single file containing both the video and audio and it's simple to drag from one device to another. It's often provided as a similar alternative to AVCHD on Sony and Panasonic cameras.
Multi pattern metering This is the most sophisticated form of light metering used by cameras. The light values are measured at many points across the frame and compared to ‘known’ scenes so that the camera can work out what the subject is likely to be and the best way to expose it properly.
Multiple exposure Taking two shots on a single frame. In the days of film this meant locking the film advance when cocking the shutter and taking another picture on a frame of film that's already been exposed. On a digital camera, the camera stores the first image in its memory and then merges it with the second.
Multi selector A control that’s practically universal on digital cameras. It’s a circular controller on the back of the camera with up/down/left/right buttons which can be used for positioning the autofocus point, menu navigation, camera settings and more.
Neutral density (ND) filter A filter which reduces the amount of light passing through the lens or reaching the sensor without affecting it in any other way. It allows longer exposures in bright daylight (useful for creative blur effects) or controls bright light in a camera with limited exposure controls.
NFC Stands for Near Field Communication, a wireless transfer system that relies on very close contact between devices – sometimes you simply tap or touch the devices together to establish contact. It can be used for transferring photos from a camera to a compatible printer, for example.
Nik Collection (DxO) An important collection of plug-ins once published by Nik Software but then taken over by Google when it bought the company. Google then made the Nik Collection free but it has now been bought for future commercial development by DxO.
NiMH battery The most common type of rechargeable AA battery, and they’ve taken over from older, less efficient Ni-Cad batteries. NiMH batteries are inexpensive and often used in cheaper compact cameras, flashguns, battery grips and LED lights.
Noir A style of photography designed to reflect the dramatic, low-key lighting of Hollywood noir films. It can be achieved with lighting or, increasingly, with digital image effects which convert images to black and white, exaggerate contrast and often add grain and a vignette.
Noise Random ‘speckling’ in an image caused by variations in the light levels captured by the photosites on the sensor. Noise is worse with the smaller photosites on small sensors and at higher ISO settings generally. You can get ‘chroma’ (coloured) noise and ‘luminance’ noise (general ‘grittiness’) the same colour as the background.
Noise reduction Camera makers use special noise reduction processing techniques to reduce the appearance of noise in photos, but the drawback is image softness and haziness and a kind of ‘watercolour’ effect where areas of fine, subtle detail are smudged beyond recognition. Bad noise reduction can do as much harm as image noise – or more.
Non destructive editing Software which doesn’t make any direct changes to the pixels in a photo, but saves processing instructions alongside it. These instructions are used to change the appearance of the photo when it’s displayed and can be applied permanently to a new ‘exported’ image.
Offline editing Increasingly, photographers need to store their images on external hard disks because there's not enough room on the computer's internal disk. This means – usually – that the external disk needs to be connected before you can do any editing work. Some software, however, can work with lower-resolution preview images while the external disk is disconnected. Capture One Pro catalogs offer offline editing, as do Lightroom's Smart Previews.
OLED display OLED stands for 'organic light emitting diode'. It's a more advanced display tech than regular LCDs with wider viewing angles, faster response, better brightness and reduced power consumption. The OLED electronic viewfinder is a selling point in the Fujifilm X-T1, for example.
ON1 Photo RAW An all-in one image organising and editing program which includes a large array of preset effects and manual tools for manually adjusting and 'stacking' effects in layers. Includes tools for black and white and portrait photography and also works as a plug-in for Photoshop and Lightroom.
Optical stabiliser Image stabiliser which moves physical elements within the lens, or the sensor itself, to keep the image steady during the exposure. This is superior to ‘digital stabilizers’ which use image processing techniques to reduce blur, but which also lead to a loss in quality.
Optical viewfinder The viewfinder in a digital SLR is optical because it’s created by an image formed by the lens on a glass ‘focussing screen’. The direct vision viewfinders on some compact cameras are optical because you’re seeing the world through a set of lenses and not via a digital display.
Optical zoom A zoom function produced by changing the magnification of the lens rather than by simply blowing up a central part of the image (digital zoom). Makers will always specify optical zoom and digital zoom separately in their specifications.
Overexposure The technical description is a picture where all the tones are squashed into the brighter end of the tonal scale and where the highlights may be completely 'clipped' (lost). The artistic description is a photo that's lighter than the photographer intended.
Overlay mode One of the most useful blend modes in Photoshop and other image editors. When it's applied to an image layer or adjustment layer it changes the appearance of the layer below. Tones darker than 50% make the those areas in the layer below look darker, tones lighter than 50% make them appear lighter. It's often used for dodging and burning effects or for increasing contrast.
Pancake lens A fixed focal length (‘prime’) lens designed to be as slim as possible so that the camera/lens combination is lighter, more compact and more unobtrusive. Their only real concession compared to a regular prime lens is maximum aperture – typically f/2.8 for a pancake lens.
Panorama Extra-wide image sometimes shot in one pass with specially designed cameras but more often these days made by stitching together a series of overlapping frames taken in quick succession as the camera 'pans' across the scene. Many cameras can now do this as you shoot.
PASM modes A set of four exposure modes that distinguishes a serious camera from simple point and shoot models. It stands for Program AE, Aperture-priority, Shutter-priority and Manual modes. You’ll find these on many better compact cameras and all DSLRs and mirrorless cameras.
Patch tool A tool in Photoshop for covering up blemishes or removing unwanted objects from pictures. You use the tool to drag out a freehand lasso around the offending area, then drag the marquee to a nearby area containing the tones or textures you want to replace it with. It can be very effective although as with all 'smart' object removal tools, it's a bit hit and miss.
Pentaprism This is a key part of the optical viewfinder system of a digital SLR. It's a five-sided prism inside a housing on top of the camera that reflects the image captured by the lens and formed on the camera's focusing screen so that it's the right way up and the right way round for viewing through the camera's viewfinder eyepiece. Some cheaper DSLRs use a less expensive 'pentamirror' design instead. It costs less to make but does have a slight effect on the size and quality of the viewfinder image.
Persona (Serif) Serif's term for the different workspaces in its Affinity Photo application. For example, you have a Develop persona for processing RAW files, a Tone Mapping persona for HDR processing, a Liquify persona and a regular Photo persona. The idea is that each persona displays only the tools you need for that particular activity.
Perspective control (PC) lens Perspective control lenses have special tilt and shift movements for correcting converging lines (shift movement) in architectural images, for example, and adjusting the plane of sharp focus (tilt movements) for objects at an angle to the camera. By applying a vertical shift you can bring the top of a tall building into the frame without tilting the camera (this is what caused the converging vertical effect). By applying a tilt movement to the lens you can change the plane of sharp focus away from the perpendicular towards the plane of your subject – this increases the depth of field available.
Perspective correction A means of correcting converging verticals in architectural shots and other perspective issues. You can get ‘perspective control’ lenses which use complex lens adjustments to fix the problem optically, or you can use software with perspective correction tools.
Phase detect AF An autofocus system that checks the position of objects from two angles. If they don't line up the object is out of focus – and the system can use the difference to work out how far to refocus the lens and in which direction. Phase detection AF sensors are used on DSLRs and now phase detection pixels are built into some mirrorless camera sensors.
Phase One Danish company which produces professional medium format cameras and lenses.
Photography Plan (Adobe) A subscription plan which includes Lightroom CC and Photoshop CC. It’s designed for photographers and does offer very good value for money compared to the old scheme, where you paid a much larger amount for a ‘perpetual’ licence, and also had to pay to upgrade to new versions.
PhotoLab (DxO) DxO PhotoLab is the replacement for the old DxO Optics Pro, adding in local adjustment tools when DxO bought the Nik Collection and its technologies from Google. PhotoLab is now a powerful all image browsing, raw processing, lens correction and editing tool, and is renowned for the image quality it can create.
Photomerge (Adobe) Image blending technology found in Adobe Photoshop, Elements and Lightroom. It's used to stitch individual overlapping frames into seamless panoramas, or to merge bracketed exposures into a single HDR (high dynamic range) image.
Photoshop Rightly regarded as the king of image-editing programs, Photoshop is the most powerful program there is for image enhancement, correction and manipulation, though it does not have the image cataloguing tools or the range of special effects offered by some rivals.
Photoshop Express A free app for tablets and smartphones that offers a selection of quick editing tools and image effects. It does not have anything like the power of the desktop program, but it can still add interesting and useful effects to your pictures.
Photosite This is the correct technical name for the individual light receptors on a sensor, though many people call them pixels because each photosite corresponds to a pixel in the final image. Each photoreceptor gathers light (photons) and turns them into an electrical charge (electrons) which can be measured.
Picture Control/Style Cameras usually offer a range of picture 'styles' such as 'Standard', for neutral results, 'Vivid' for richer colours, 'Portrait' for gentler tones and more. These are applied to JPEG images saved by the camera. If you shoot RAW files you can choose the picture style later on.
Pincushion distortion This is where straight lines near the edge of the picture appear to bow inwards. It’s not as common as barrel distortion, but you do see it quite a lot with telephoto zoom lenses when the lens is set to its maximum focal length. You may not notice it with many types of subject, but it can be corrected with software later anyway.
Pixel The individual building block of digital images. Each individual pixel is a single block of colour, but when there are enough of them viewed from far enough away they merge to form the impression of a continuous-tone photographic image.
Pixelmator Low-cost image-editor for Mac and iOS which has a clean and simple interface but powerful editing, retouching, selection and layering tools and a range of customisable effects. It also has painting tools and vector drawing tools, making it equally suitable for art projects, illustrations and diagrams.
Plug in A software tool designed not to be used on its own, but as an add-on to programs like Photoshop and Lightroom. Plug-ins typically offer specialised tools and effects not usually found in regular image editing programs.
Point and shoot camera It’s about the easiest way of describing simple digital cameras that are inexpensive and designed for novices. They offer fully-automatic shooting modes that don’t require any particular photographic know-how and zoom lenses which cover most everyday needs. They quality is only average, though, and there’s little scope for overriding the camera.
Polarizing filter Polarising filters darken blue skies and can cut through reflections and glare in water, glass and polished surfaces. They come in two types: linear polarisers are cheaper and older and don't work well with modern autofocus systems; circular polarisers are more expensive but they are the type needed for modern cameras.
Pop up flash Most cameras have a built-in flashgun which pops up automatically in low light or can be popped up by pressing a button. The flash can provide emergency light, but it's harsh and short range. In many instances it's best to leave the flash off and use higher ISO settings.
Portrait lens As the name suggests, this is a lens particular suited to portraiture by virtue of its focal length and a fast maximum aperture.
Post crop vignette Normally, if you apply a vignette effect to a photo and then crop the photo you will crop off some of that vignette effect at the edges, too. However, Lightroom's 'post-crop' vignette will re-apply the vignette settings after the image is cropped so that you don't lose the effect. MacPhun's Luminar has a Vignette filter which offers both modes – pre-crop and post-crop vignette.
PowerShot (Canon) The brand name for Canon’s more advanced compact digital cameras. They include long-zoom compacts, bridge cameras and Canon’s more sophisticated high-end compact cameras, which feature extensive manual controls and larger sensors.
Predictive autofocus Here, the camera tracks subject in continuous autofocus mode and uses its movement within the frame and any changes in its distance from the camera to work where it’s going to be at the moment the shutter fires.
Preset Specific adjustment settings, or groups of settings, saved for re-use. Presets are used widely by image-editing and effects software to apply a sophisticated set of adjustments to a photo with a single click.
Prime lens A lens with a fixed focal length, as opposed to a zoom lens. Prime lenses are more restrictive, but they tend to produce better optical quality with fewer aberrations and offer a wider maximum aperture. They also tend to be lighter and smaller, and many photographers find that having to change position to get the best framing leads to better pictures.
Printer calibration Printers don’t always produce accurate colours, particularly when using third-party papers or inks. A printer calibration kit will measure the colours produced by the printer and then create a software printer profile which adjusts the colour data sent to the printer.
Program AE (P) mode In this mode, the camera chooses combinations of shutter speed and lens aperture automatically to give a good compromise between safe shutter speeds (no camera shake) and reasonable depth of field (smaller apertures).
Program shift An override option in program AE mode which shifts the shutter speed and aperture combinations in favour of faster shutter speeds or smaller apertures. This is often quicker than swapping to aperture-priority or shutter-priority mode if it’s for a single picture.
This is a clear glass filter that has no optical function at all but is simply designed to protect the front element of the lens from dust, smears, scratches and moisture, even impacts. Protection filters screw directly into the lens's filter thread, so you will need to get one the right size. You can also use UV filters as protection filters, although the UV filtering is hardly relevant today.
Q (quick) menu A useful feature on some cameras which puts all the most commonly used camera settings on a single screen. You can then use the cursor buttons to quickly select the setting you want and change it. It's a pretty common option across all cameras, though the name may be different.
Quadcopter A type of drone which uses four independently powered rotors. This is the most common type available to consumers though there are drones which use more rotors in order to achieve greater lifting power. When people say ‘drone’ they usually mean quadcopter.
Quick release (QR) plate This is an attachment for tripod heads designed to make it quicker to remove the camera for handheld photography and re-attach it. You attach the quick release plate to the camera with a slotted screw or butterfly nut, then clip the quick release plate on to the tripod head with a sprung catch or a locking screw. Quick release plates come in different types, but the closest to a universal standard is the Arca Swiss plate.
Quiet mode A very useful option if you need to take pictures in a theatre, church or museum where it's important to make no noise. Some Nikon DSLRs have a Quiet mode, though you can't completely eliminate the noise from a DSLR's shutter or mirror mechanism.
Radial mask A circular/elliptical selection, or mask, which you can move around the photo and resize to get just the effect you want. Typically, you can adjust the area inside the radial filter or outside it. It’s a quick and effective way to ‘relight’ a photo or concentrate attention on the main subject.
RAID drive RAID drives are a high-end desktop storage system that offers extra speed and security, but in larger drive units that are also considerably more expensive (and noisier) than regular types. They use two or more hard disk drives working in unison to offer data 'redundancy’, so that if one drive fails your data is still stored across the others. They can also offer much faster data transfer rates than regular hard drives, which can be especially useful for video editing.
Rangefinder An older camera designed still used by celebrated German manufacturer Leica. The ‘rangefinder’ is used for focusing – as you turn the focus ring on the lens, a small mirror in the top of the camera rotates to line up a ‘ghost’ image with the main image in the viewfinder. When this ghost image lines up, your subject is in focus.
RAW+JPEG Cameras with the ability to shoot RAW files will almost always offer a RAW+JPEG option too. Here, the camera shoots a single image but saves two versions – the RAW file and a JPEG processed and saved with the current camera settings. The JPEG is useful because you can share it with other people straight away and it also offers a useful benchmark when you're processing the RAW file later.
RAW converter Software that processes RAW files from a camera and converts them into regular image files. Not all RAW converters are the same. The closest analogy is the different developers used to process film. Examples include Adobe Camera Raw, Capture One Pro and DxO Optics Pro.
RAW file Usually when you take a picture the camera will process the data captured by the sensor into an image file. More advanced cameras can save the image in its unprocessed state – a RAW file – so that you can do the processing yourself later on your computer.
RAW vs JPEG Most digital photos are shot as JPEG images. This is a universal image file format that uses sophisticated compression to keep the files small and manageable. JPEGs are created by processing the RAW data captured by the camera. Some cameras let you save these RAW files instead. The files are larger and you need to process them later on a computer, but they offer the potential for better quality.
Rear curtain flash A special slow sync flash mode which fires the flash at the end of the exposure not the start. This gives more natural-looking results with moving subjects because any movement trail will be behind your subject and not ahead of it (which looks odd).
Recycle time The recycle time is the time taken by a flash to build up the power for the next flash after it's just been used. Flashguns work by accumulating a large electrical charge which is then discharged in an instant via the flash head.
Red filter Used in black and white photography to darken blue skies and lighten skintones and foliage. It can produce dramatic, high-contrast images.
Referenced files Image cataloguing programs which use a central database to keep track of all your photos store both a representation of each photo and its location on your computer. Some programs will offer to import the photos into a central, 'managed' library, but usually they will simply 'reference' your files in their current location.
Reference View (Lightroom Classic) A new view in Lightroom that lets you place a ‘reference’ image alongside the one you’re working on, so that you can match the overall look and feel – this could prove very useful if you’re trying to achieve a consistent ‘look’ across a series of pictures.
Reflector A reflector is a kind of lighting modifier designed to reflect light back towards your subject. Usually it's a white or foil-covered disc stretched tight across a circular wire rim. When the reflector's not being used it can be twisted into a much smaller disc and stored in a circular carry case.
Remote A device which fires the camera’s shutter release from a distance, either via an electrical cable or a wireless signal. It’s useful if you need to stand some distance away from the camera and avoid jogging the camera when you fire the shutter.
Reproduction ratio Reproduction ratio is a term used in macro photography to indicate the degree of magnification. A ratio of 1:1 is usually considered the minimum for 'true' macro photography. This means that an object is reproduced at exactly the same size on the sensor or film surface as it is in real life. If the first number is higher, e.g. the reproduction ratio is 2:1, it means the lens can reproduce objects at twice life size. If the second number is larger, e.g. 1:2, it means objects are reproduced at half their actual size.
Resampling Changing the pixel dimensions of a photo, usually to reduce the file size for sharing or online use. Resampling is irreversible because it changes the pixels in the photo. If you resample an image down to a smaller size, there's no way to return it to its original form – the pixels discarded in this process can't be restored.
Reset (camera) More advanced digital cameras have many shooting and setup options – so many, that you can sometimes forget what you’ve set them up to do. To get back to the default settings you need two options: 1) Reset shooting settings; 2) Reset custom settings.
Resizing 'Resizing' and 'resampling' sound the same but they're not. 'Resizing' an image means usually means changing the size at which it will be printed, not changing its actual pixel dimensions. So for example you can 'resize' a photo to print it as a 6" x 4" or a 12" x 8". The only thing that changes is the number of pixels per inch in the final print. Some programs blur the distinction between 'resampling' and 'resizing' so it's important to make sure you understand what they're about to do.
Resolution This can mean one of several things depending on the context. Camera resolution is the number of megapixels on the sensor, lens resolution is how well the lens is able to resolve fine detail. Screen resolution is the number of dots on the screen and therefore how sharp/clear it looks.
This is the name of a filter range created by filter maker H&Y filters. Instead of using a filter thread of a fixed size, it houses a spring-loaded mechanism that can adapt to a wider range of filter sizes, making it possible to use one filter with a different number of lenses. You still have to choose different Revoring sizes to handle small, medium and larger lens sizes.
RGB RGB stands for red, green and blue, the three colour 'channels' that go to make up all the colours in a digital image. It comes in two varieties – sRGB is a 'universal' RGB that can be used and displayed by any device, whereas Adobe RGB is a more specialised alternative for pros.
Rig (video) In video, a 'rig' is a harness, a camera mount, a gyroscopic stabiliser or any apparatus designed to make it easier to carry and use a video camera. A rig may also have mounting points for video lights and microphones.
Rolling shutter An image distortion effect caused by the way camera shutters operate at very high shutter speeds. Beyond a certain speed, focal plane shutters, as used in most interchangeable lens cameras, change the way they work. Instead of exposing the whole sensor at once, they expose it in a narrow strip between two shutter curtains passing very quickly across the sensor. This means that if a subject is moving very rapidly it may take on a skewed or twisted shape. This can be apparent not just in stills photography but in video too.
Round tripping This is where you temporarily send a photo to a different image-editor or plug-in to carry out adjustments you can’t do in the software you’re using. When this external editing is complete, the picture is returned back to the original program – a ‘round trip’.
Rule of thirds A ‘rule’ of composition that says that pictures look best if objects are placed one-third of the way in from the edge or top/bottom of the picture, rather than being placed directly in the centre. It can be helpful, though calling it a ‘rule’ gives it more importance than it deserves.
Run and gun (video) A style of videography where you're not shooting from a static position, but following the action on foot as you film. You'd typically use it for action sequences. It takes a good deal of skill and it's best used for deliberate effect, not simply to make up for any lack of planning or direction!
S-AF (single shot AF) mode Here, the camera focuses once when you half-press the shutter release then holds that focus point until you press the button the rest of the way to take the picture. This is the usual mode for taking one photograph at a time (as opposed to continuous shooting).
Safe shutter speed A shutter speed fast enough to prevent camera shake during the exposure. Normally, it’s a second divided by the effective focal length of the lens, so for a 60mm lens a shutter speed of 1/60sec should be ‘safe’. The advent of image stabilisers, however, has made it possible to get sharp handheld shots at much slower shutter speeds.
Saturation The intensity of a colour or a photo. The higher the saturation, the more intense the colour. You can increase the saturation of a photo, but at a certain point the stronger colours will start to 'clip' – objects lose any fine detail and become a solid block of colour.
Scene mode Automatic mode designed for beginners where the camera applies the settings that best suit the subject you’re shooting (landscape, portrait, action etc). Some cameras can analyse the scene in front of you and choose a scene mode automatically. Experts don't normally bother with scene modes because they're designed solely for those who don't really want to get involved with individual camera settings. If you do know your way around a camera, you'll generally want to make your own choices about the settings.
SD/SDHC/SDXC card These are all the same size but there are important differences. Older cameras may only be able to use SD cards, but more recent ones will be able to use SDHC cards too, but may not be able to use the latest SDXC format. Check your camera’s manual before buying these.
Selection A way of separating out a specific part of a picture for adjustments. Selections can be made using a variety of tools such as a rectangular or circular marquee, a magic wand or a selection brush. When the selection is made, it has an animated, dashed outline sometimes called ‘marching ants’.
Selective color A special effect which converts the whole image into black and white except for one specific colour range. One the the most common examples is a black and white image with a bright red subject – the girl in the red coat in the film ’Schindler’s List’, for example.
Selfie Popular feature on smartphones, compact cameras and many mirrorless models. On a smartphone you use the front-facing camera so that you can see yourself on the screen as you compose the shot. On regular cameras you use a flip-up/flip out screen and face it to the front.
Selfie stick Horribly popular gadget that mounts your camera or smartphone on the end of a what is essentially a lightweight monopod – some are rigid, some have extendable sections. The camera can be fired using the self-timer or, sometimes, by a built in remote release.
Self timer The camera waits for a set delay before firing the shutter. This gives the photographer time to get in position for a group shot – but it’s also useful for tripod shots or long exposures where you want to fire the shutter without jogging the camera.
Sensor basics There are two main things to look for in sensors: the sensor size and the resolution, in megapixels. It’s more important to get a bigger sensor than to get more megapixels.
Sensor cleaning DSLRs and compact system cameras sometimes collect spots of dust on the sensor. The makers get round this by applying a high-frequency shaking action to the sensor to shake it off. This happens automatically when you switch the camera on or off but you can also start it manually.
Sensor size This is the physical size of the sensor, which is independent of the number of megapixels it has. Bigger sensors capture more light and produce sharper, clearer images with less noise. In fact sensor size is the single most important factor these days in a camera's picture quality – megapixels are mostly secondary.
Sepia toning An old black and white darkroom technique that turns regular black and white prints a vintage brown. It also adds depth and richness to monochrome images. These days it's an effect that's easy to create digitally and is just one of a number of popular toning effects.
Serif Previously known mostly for its budget design and illustration software, Serif has now branched out into professional design and image-editing with its state of the art Affinity range.
Session (Capture One) Capture One is Phase One's professional image capture, organising and editing application. It started out as a tethered shooting tool for studio photographers, capturing each shoot as a 'session' where photographers could quickly sort through images, marking some as 'picks' and rejecting others. Capture One now offers Lightroom-style image catalogs but still offers its Sessions mode for photographers who prefer to work that way.
Shadow and highlight recovery Feature on some cameras and in some image-editing programs that lets you recover very bright or dark areas of the picture which would otherwise be lost to over- or under-exposure. It uses the extra image data captured in RAW files, so you have to shoot RAW to be able to do this later on a computer.
Shadows The darkest tones in a picture. A pretty vague term (like ‘highlights’) but usually taken to mean the darkest areas where you can still see some image detail. Digital cameras often retain more shadow detail than you can see initially, and this can be brought out later on a computer.
Sharpener (Nik Collection) Software plug-in for sharpening images and part of the Google Nik Collection. It comes in two parts – Sharpener Pro Raw Presharpening for enhancing images straight from the camera, and Sharpener Pro Output Sharpening for preparing images for printing on different devices.
Sharpening A standard part of digital image processing either in-camera or later on a computer. Sharpening processes increase the contrast around object outlines to make them look crisper. Good sharpening is all but invisible, bad sharpening leaves edge ‘halos’ you can see under magnification.
Shotgun mic A shotgun mic is a highly directional microphone usually used to capture audio from a subject a little way from the camera. They're popular for on-camera use when it's not possible to place a microphone on or near your subject. Shotgun mics are 'unidirectional', which means they capture sound from one direction only over quite a narrow angle. This makes them more effective at excluding unwanted background noise.
Shutter The mechanism that control the length of the exposure. On some smaller cameras this may be in the lens (a ‘leaf’ or ‘in-lens’ shutter), but on DSLRs and mirrorless cameras with interchangeable lenses, it’s a ‘focal plane’ shutter directly in front of the sensor.
Shutter priority (S) mode Exposure mode where you choose the shutter speed and the camera selects a lens aperture to give the correct exposure. You get to choose the shutter speed manually, but the camera still takes care of the exposure automatically. On Canon cameras this is called Tv (time value) mode.
Shutter speed The length of time the shutter is open during the exposure and usually quoted as fractions of a second. Each shutter speed is half as long as the one before, for example 1/30sec vs 1/60sec. This exposure ‘halving’ is the basis for balancing up lens aperture and ISO settings. A few cameras have external shutter speed dials but most simply display the shutter speed on the LCD display – you turn a control dial to change the speed.
Silent mode A useful mode if you’re shooting in a theatre or museum, but one that’s only available on compact cameras with in-lens shutters and mirrorless cameras with electronic shutters. On compact cameras you can get the same effect by turning off the focus ‘beep’ and shutter sounds.
Silver Efex (Nik Collection) Software plug-in for creating authentic-looking black and white film looks, and part of the Google Nik Collection. Silver Efex Pro can replicate the look of classic black and white materials and darkroom effects. It also offers 'control points' for localised dodging and burning.
Slow flash/slow sync Special flash mode where the camera’s exposure is extended beyond the brief burst of the flash. This makes it possible to record some of the ambient lighting too, and it’s a popular technique for illuminating a nearby subject brightly without losing background colour and detail.
Slow motion Video shot at a higher frame rate and played back at a normal frame rate. For example, video shot at 60fps and played back at 30fps would appear to be running at half speed. Higher frame rates require more processing power, so not all cameras offer them.
SLT (single lens translucent) SLT cameras are made by Sony as a kind of hybrid of the regular digital SLR design and the always-on live view of a mirrorless camera. They do have a mirror in the body, but it doesn't flip up and down when you fire the shutter. Instead, it has a translucent surface so that the image can pass straight through to the sensor on the back of the camera.
Smart album/collection An album or collection in a photo organising application that automatically brings together images that match the properties you choose. For example, you could have a smart album/collection containing pictures shot on a Sony A7 camera in the RAW format with the keyword ‘winter’.
Smart Lighting (DxO) A feature in DxO Optics Pro that attempts to optimise exposure levels and highlight detail retention in RAW files. You can adjust the strength of the effect and apply exposure compensation at the same time, to get the ideal result.
Smartphone Many smartphones have pretty good cameras. The best ones have sensors about the same size as those in point and shoot cameras and fixed focal length lenses. The lack of a zoom is a restriction, but otherwise the quality is just as good. There’s even a growing art movement around mobile photography.
Smart Preview (Lightroom) With Lightroom's Smart Previews you can store smaller, lower-resolution versions of your photos within the Lightroom catalog while storing the full resolution versions on an external disk drive. Smart Previews are compressed DNG files and fully editable – any changes you make are automatically used for the full resolution photo when your drive is reconnected. Smart Previews make it practical to view and edit your image library on a laptop with a relatively small internal drive.
SmugMug An online photo sharing/portfolio website designed for photographers to display their work, create online portfolios and sell images.
Snapshot (editing) A Snapshot is a record of the current image state while you're editing it. You can create a Snapshot in Photoshop or Lightroom when you reach a point that you think you might want to return to during editing. You can save a number of Snapshots to quickly compare different editing steps.
Softbox A softbox fits around the head of a flash to provide a larger and more diffuse rectangular light source. It's very popular amongst professional photographers for product shots, where it produces even lighting and nice reflections off glossy surfaces, and for portrait photographers who want to achieve a softer, more flattering effect.
Soft focus An effect often used for portrait photography which gives a flattering or glamorous look to female faces. There's more to it than just defocusing the picture, though - soft focus filters add a soft haziness to highlights and areas of even tone but preserve the underlying image detail.
Solarization A technique for reversing the tones in the brightest parts of the picture to produce a 'semi-negative' photo. It can create a very dramatic and surreal effect. It used to be done in the darkroom by re-exposing a print to light part-way through development, but can now be done much more controllably using software.
Sony Sony is best known as a giant electronics manufacturer making devices across a range of markets, but its camera division is doing especially well. The market for compact point and shoot cameras has fallen, but Sony is doing very well with its professionally-orientated full-frame A7 series and A9 cameras. It also makes a continually expanding range of high-end professional lenses.
Speedlight/Speedlite The names used by Nikon and Canon respectively for their camera flash units, both built-in pop-up flash and external flashguns. There’s nothing intrinsically different about these compared to regular flashguns – it’s just a different choice of name.
Spikes (tripod feet) Tripods usually come with rubber feet on their legs, but these may not give much grip or purchase if you're using them outdoors on soft or uneven surfaces – this is where it's often better to have a metal spike instead. On some tripods, the rubber feet will screw back to expose a spike. On others, you may be able to unscrew the rubber feet and screw on spikes instead.
Split toning A more complex type of toning where two colours are used not one – shadows are tinted with one tone and highlights with another. The results can be very effective, though it’s not always easy to find good-looking toning combinations and split toning doesn’t work with all images.
Spot healing brush This is a tool for simply brushing away blemishes, sensor spots or unwanted objects in your pictures. You can 'dab' once with the brush for spots or paint over irregular objects. It uses pixels from surrounding areas to fill in the gap, and it works really well with small objects against larger backgrounds. It's less effective at larger repairs, but worth and try nonetheless.
Spot metering A metering mode where the camera measures the light from a very small area of the scene. This might be right in the centre or, on some cameras, it’s directly beneath the selected autofocus point.
Spot removal Cameras with interchangeable lenses do not have sealed interiors and the sensors can pick up spots of dust. These can be removed in software using spot removal tools – you dab on the dust spot and the software uses nearby pixels to cover it up. It's like cloning but easier, because you can leave the software to 'heal' the spot automatically.
Square filters are designed to be used with filter systems, slotting into a filter holder which attaches to the front of the camera lens. This system of holders, slots and square filters means that filters can be used in combination, and filters that need to be positioned vertically – notably graduated filters – can be moved up and down the slot for precise positioning.
SSD A solid state storage device that uses memory chips rather than a hard disk. SSDs offer much faster data transfer rates than regular hard disks, they’re smaller and have no moving parts. They are, however, much more expensive, so while an SSD is ideal add-on storage for desktops and laptop computers, especially if you want to take your data with you on the move, they are a substantial investment.
Stacking/grouping images A way of keeping related images together in an image cataloguing program – such as different exposures in a bracketed series, the individual frames of a panoramic image, the shots from a continuous shooting sequence or edited and original versions of a photo. Adobe Bridge can stack images, as can Lightroom. Apple's now-discontinued Aperture offered the most consistent and versatile stacking system.
Standalone software Software that you launch directly and which doesn’t need any other program to run – as opposed to plug-ins, which need a ‘host’ application.
Status LCD More advanced DSLRs have a secondary LCD display on the top so that you can check the main shooting settings without needing the rear screen. Status displays are black and white (or black on green) and usually have a backlight button for use in dark conditions.
Stepping motor As the name suggests, stepping motors move in small, incremental steps. They are simple, reliable and offer a good deal of control and precision. They're now being used by Canon (STM lenses) and Nikon (AF-P lenses) in a number of consumer-orientated lenses, where they offer fast, quiet and smooth autofocus.
Step up rings are used to fit a larger filter on to a smaller lens filter thread. They are a useful way to reduce the number of different filter sizes you need to get. They are inexpensive to buy and they are available in just about any combination of lens filter thread and filter size.
STM (Canon) STM stands for stepper motor lenses, a new type of autofocus motor used by Canon in some of its lenses. Stepper motors offer fast, precise and quiet focus adjustments, so these lenses are well suited both to regular stills photography and to video, where autofocus noise can be picked up very easily by the camera's internal microphone. Canon's STM lenses work very effectively with cameras using Canon's Dual Pixel CMOS AF autofocus system.
Stock photography Generic images offered for sale to anyone who wants to license them for use on websites or in publications. Stock images are generally submitted to a searchable stock library by individual photographers. When a client pays to use an image, the photographer gets a percentage of the fee.
Straightening images It's very easy to accidentally shoot with the camera slightly skewed so that horizons or vertical objects aren't straight. Most photo editing apps have a simple Straighten tool to put this right.
Structure A detail enhancing adjustment that emphasises object outlines by adjusting local contrast over a larger radius than regular sharpening tools. It makes finer details more prominent.
Style (Capture One) Capture One offers two kinds of one-click adjustment and a slightly different terminology to other programs. In Capture One you can create custom settings for each of its tools and save this as a ‘Preset’. Capture One Presets use a single tool. But you can also combine multiple Preset adjustments to save a ‘Style’. Phase One sells a number of different Styles packs designed by professional photographers and for use with Capture One.
Subject tracking AF A focus mode where the camera continually refocuses on a moving subject. The more advanced the AF system, the better it will be at keeping the subject in focus. It’s used mostly in continuous shooting mode for sports and action photography but can also be used for video.
Subscription software A new way of paying for software where you pay a monthly or a yearly subscription rather than paying a single sum for a licence to use the software for as long as you like.
Super telephoto An extreme telephoto lens with an effective focal length of 400mm or longer and most commonly used by sports, wildlife and press photographers. These lenses are big, heavy and expensive but provide high levels of magnification not possible with ordinary lenses. Some consumer-orientated 'bridge' and 'travel' cameras have very long zoom ranges that fit into this category, though the small size of the sensor and limited optical quality of the lenses stops them being taken seriously alongside professional cameras.
Sync terminal/socket A cable connector for socket external flash units that’s still found on higher-end cameras like pro DSLRs but is becoming less and less common as photographers switch to wireless flash systems. These are usually triggered by a ‘master’ unit attached to the camera.
Teleconverter A special magnifier lens that fits between a telephoto lens and the camera body to increase its focal length. Teleconverters are often matched to specific lenses to ensure optical quality and performance. They typically come in 1.4x, 1.7x and 2x magnifications.
Telephoto A lens which gives a magnified view of the scene. The magnification is proportional to the focal length of the lens, so a 100mm telephoto gives 2x the magnification of a 50mm standard lens.
Tethered shooting A technique used by professional studio photographers where the camera is connected to a computer and the computer is then used for controlling the camera, checking pictures as soon as they’re taken and then correcting and enhancing them as necessary before saving.
Three way head A three way tripod head has separate adjustments for horizontal movement (pan), fore and aft movement (tilt) and camera orientation (vertical or horizontal). This makes a three way head heavier and more bulky than a ball head, but it's easier to make precise, fine adjustments in one direction only.
TIFF format An image file format that uses ‘lossless’ compression but produces much larger files than JPEGs. It’s sometimes offered as a file format on more advanced cameras but it’s more useful later on as an image file format for image editing and manipulation on a computer.
Tilting screen One that tilts up and down but doesn’t flip out and rotate in all directions (an ‘articulating’ screen). Tilting screens are nonetheless useful for composing pictures with the camera at waist or ground level or above head height.
Tilt shift A specialised type of lens which can be tilted relative to the camera body. This changes the plane of sharp focus and can be used to extend or contract the available depth of field. It can also be simulated digitally using tools which leave a central strip of the photo in sharp focus but progressively blur the rest of the image towards the edges.
Time (T) exposure A close relative of the bulb (B) shutter speed setting and, like bulb mode, it’s used for long exposures. With time (T) exposures, though, you don’t hold the shutter button down all the time – you press once to start the exposure and a second time to end it.
Timelapse A filming technique where frames shot at intervals are combined to make a video. For example, if you shot 300 frames at 1-second intervals and turned them into a movie running at 30fps, then five minutes of real time would be compressed into a 10-second movie.
Tint (white balance) A secondary white balance adjustment used alongside colour temperature for more complex light sources like fluorescent lighting. Colour temperature works across an amber-blue spectrum, while tint adds a green-magenta axis.
Tonemapping A technique used by HDR software to 'map' the extremely wide brightness range of a high dynamic range image into an editable form where the extremes of shadow and highlight detail are preserved. It's usually the first and sometimes the only step in making an HDR image.
Toning Adding a coloured tone to black and white pictures to add depth or atmosphere. The most famous is sepia toning, so often used for Victorian portraits. These days most people simulate toning effects digitally using colour controls and effects filters.
Topaz Labs Software company which publishes the Topaz Studio plug-in effects collection where you can try basic versions of each tool and upgrade to the full versions of those you want individually.
Touch AF Autofocus mode where you tap on a touch-sensitive screen to choose the focus point for the picture. Some cameras also offer a touch shutter option where tapping the screen not only sets the focus point but fires the shutter too.
Touchscreen Pretty self-explanatory really – an LCD screen offering touch control for camera settings, setting the focus point, menus and more. These are becoming increasingly popular on compact cameras and mirrorless models as a way of supplementing or replacing knobs and dials.
Toy camera effect A deliberately low-quality image effect that mimics the retro look produced by cheap old film cameras. Pictures have added contrast and colour saturation and strong vignetting at the edges of the frame. Some toy camera effects add a colour shift to simulate old and out of date film.
Transform Changing the perspective or scale of a photo or objects within the photo. Typically it can include straightening, scaling up and down, skewing or correcting converging verticals, for example.
Travel camera A more advanced version of a point and shoot camera with a much longer zoom range and, sometimes, more advanced photographic controls. The 20x or 30x zoom range makes these cameras much more versatile, but they use small sensors so the picture quality is limited.
Travel tripod Travel tripods are designed for compactness and light weight so that they can more easily be strapped to bags or even carried inside them. They have a specific design feature, whereby the legs fold upwards around the centre column and the tripod head to minimise their size when folded.
Tripod Three-legged camera support that doesn't really need much more explanation, except to say that they vary considerably in cost, size and rigidity, and that some come with tripod heads while others require you to buy them separately.
Tripod head This is the part on the top of the tripod that allows you to move the camera and then lock it in position. You can get ball heads, which allow free movement in all direction but not much precision, or three-way heads which are slower to use but enable you to move the camera in one axis at a time.
Tungsten lighting An old-fashioned form of continuous lighting once used extensively in studio and portrait photography but now superseded by more powerful and energy-efficient flash systems.
UHD video This is what most people are referring to when they talk about ‘4K’ video. UHD video has a frame size of 3,840 x 2,160 pixels, so it’s slightly less than 4,000 pixels wide, but it does have a true 16:9 aspect ratio, so the picture proportions are the same as standard HD and full HD video.
UHS is a new ultra high speed bus (data transfer connection) for SD memory cards. There are two versions: UHS-I and a more advanced UHS-II type. This refers to the physical construction of the card and does not directly indicate its speed. There are speed standards for UHS cards: UHS 1 guarantees a minimum speed of 10MB/s, which is suitable for full HD video recording, and UHS 3 guarantees a minimum transfer speed of 30MB/s, which is what you’d need for 4K video.
Ultra wideangle A lens with a much wider angle of view than your camera's kit lens. In 35mm camera terms, a super-wideangle lens is one with a focal length of around 20mm or less. Super-wideangle lenses are quite expensive and characterised by large, bulbous front lens elements.
Underexposure Where a picture comes out darker than you expected because of the way the camera has adjusted the exposure, or where you deliberately make the photo come out darker for dramatic effect.
Upright tool (Lightroom) A set of perspective controls which can correct converging verticals, skewed horizons and other perspective problems. Lightroom offers a set of automated one-click buttons which often fix the problem immediately, plus a manual tool for correcting more complex or difficult perspective problems.
USB Standard connection between cameras and computers, though these days most photographers would remove the memory card and use a card reader to transfer photos. USB ports can also be used for charging on some compact cameras and ‘tethered shooting’ on professional cameras.
UV filter Almost colourless filter which is designed to cut blue (UV) haze in distant scenic shots, though this is less of an issue with digital imaging than it was with film. UV filters are still used, though, as a simple and inexpensive lens protector.
Variable ND filter Variable ND filters are useful in video because here it's often important to maintain the same aperture (iris) setting and shutter speed (or 'shutter angle') to keep a consistent visual effect even in changing lighting – you can adapt to different light levels by adjusting the ND effect.
Variant (Capture One) Used in Capture One Pro to create different versions of a photo without physically duplicating the image file on your hard disk. Capture One Pro's adjustment are non-destructive, which means they consist of processing instructions rather than direct adjustments to image files. Lightroom has a similar feature called 'Virtual Copies’.
Vibrance A more sophisticated version of the regular saturation adjustment which targets the weakest colours rather than applying a constant saturation increase across the whole range. It’s less likely to produce solid, ‘clipped’ colours and can give a more natural, more controllable colour boost.
Video Almost all digital cameras can now shoot video as well as stills, and as well as its leisure applications, video is also increasingly important to professional photographers as clients frequently want movies as well as still images. The key specifications are the resolution (standard HD, full HD or 4K) and the frame rates (30fps, 25fps or 24fps). Some cameras offer faster frame rates for slow motion effects. High-end cameras offer 6K or, soon, 8K resolution and it's also possible to get 360-degree video cameras no larger than GoPro style action cams.
Video light A lighting unit designed specifically for video, typically small and light enough to mount on the camera or alongside it on a video rig. Some flashgun makers are now building a small video light into their flash units.
Viewfinder coverage The percentage of the scene shown by the viewfinder. In better DSLRs you see 100% of the scene that will be captured, but in cheaper models it might only be 95-97%. That small difference can lead to objects showing at the edge of the frame that you hadn’t realised were there.
Viewfinder grid These are an option on both DSLRs and in electronic viewfinders. You can use the grid to make sure horizons are level and buildings are vertical – some grids confirm to the ‘rule of thirds’ to help you get a satisfying composition.
ViewPoint (DxO) Software that corrects distortion using lens correction profiles, fixes volume deformation created by wideangle lenses and offers perspective correction tools for fixing converging verticals and more. Works as a standalone app or as a plug-in and also integrates with DxO Optics Pro.
Vignette An effect where the edges of the picture are darker than the centre. It was common with old lenses and it's become associated with a vintage look. It's considered a lens aberration these days, though photographers often like to add a vignette effect deliberately.
Virtual Copy (Lightroom Classic) Because Lightroom uses non-destructive editing, its adjustments are stored as metadata (processing instructions) rather than new image files. This means it can create any number of Virtual Copies of the same image for trying out different effects, without having to duplicate the image itself on your hard disk.
Virtual horizon A kind of on-screen spirit level that shows you when the camera is level. This can be useful in landscape photography, for example, when the horizon isn't flat or visible. Some also have fore-and-aft levels to help avoid any tilt (and converging verticals) when shooting buildings.
Viveza (Nik Collection) Viveza is a software plug in which offers localised adjustments for photos via 'control' points. It's part of the Nik Collection. You can use it to apply dodging and burning effects to enhance colour images in just the same way you would in black and white.
Volume deformation A special type of distortion correction once built into DxO Optics Pro but now built into the separate DxO ViewPoint application. It fixes the distortion usually seen with wideangle lenses where objects near the edge of the frame appear disproportionately wide – it's most obvious with human figures.
VR (Vibration Reduction) (Nikon) Nikon's name for its image stabilisation technology, as built into its DSLR lenses. Tiny gyroscopic sensors detect any camera movement during the exposure and instantly shift a group of internal lens elements to compensate and keep the image steady on the sensor.
Warmth A non-technical way of describing the colour temperature of the light in a scene. Pictures taken with a low sun have ‘warmth’ because the light takes on a golden colour. Many photographs – landscapes, for example – can be enhanced with a little additional ‘warmth’.
Watermark A way of marking images as your own property to prevent others from passing them off as their own or earning income from your work. Watermarks are visible on the image, which is a downside, but they do act as a visible deterrent and warning that you take image copyright ownership seriously.
Watt seconds Watt-seconds is the usual measurement for the power output of professional flash systems. 1 watt-second is equivalent to the power of 1 watt for a period of 1 second. It's used because it's a measure of raw power output independent of any lighting modifiers, angle of coverage or reflective surfaces.
White balance An adjustment made by the camera to neutralise colour shifts in the lighting. Digital cameras offer an auto white balance option where they choose the correction, or you can select manual white balance ‘presets’ when you want to control the camera’s colour rendition yourself. White balance adjustments are made using 'colour temperature' and 'tint'.
Wi-Fi An increasingly common feature on digital cameras at all levels. The camera sets up a Wi-Fi hotspot which you can then connect to with a smartphone or tablet. The camera maker supplies an app which you can use for transferring photos to the device and for controlling the camera remotely.
Wideangle lens A lens that takes in a wider than usual angle of view. Wideangle lenses have an effective focal length of 28mm or shorter. The shorter the focal length, the wider the angle of view.
Wind cut A feature on some microphones that attempts to cut out loud roaring, whistling noise that you might not notice when shooting but which spoils the sound quality. It can be effective, but it’s even better to use a muffler on an external microphone.
Workspace Highly complex photo-editors offer so many tools that the interface can quickly become cluttered and confusing. To get round this, most offer the ability to produce a custom workspace containing only the tools you use most often.
X-mount (Fujifilm) This is the lens mount for Fujifilm's X-series mirrorless cameras. These include the Fujifilm X-T2, X-H1, X-E3 and others. Any X-mount lenses can be used on any X-mount camera, though note that Fujifilm's medium format GFX 50S uses a different mount and different lenses.
X-trans sensor A sensor layout unique to Fujifilm which replaces the usual bayer pattern of red, green and blue photosites with a more 'random' arrangement. Fujifilm says this eliminates the need for a low-pass filter to combat moiré (interference) effects, resulting in sharper fine detail.
XQD card An extra-fast memory card format currently used only in the Nikon pro DSLRs. It’s about half the size of Compact Flash but has the potential for extremely high speeds – though it’s yet to be seen whether many other camera makers will adopt it.
Yellow filters were a popular choice for black and white landscape photography. Like other contrast filters, they pass through the filter color but hold back complementary colours. In landscape photography, that means blue skies are made darker while yellow tones, including most foliage, keep their brightness. A yellow filter is one of the most popular black and white filters, along with the red filter.
Zebra pattern A visual warning that image highlights are being overexposed and used especially during video recording. The overbright areas are marked by moving diagonal stripes (hence zebra) leaving you to decide whether to reduce the exposure or to leave it if the highlight areas are unimportant.
Zone System A system developed by the great landscape photographer Ansel Adams for measuring the light levels throughout a scene and allocating them to ten brightness 'zones'. The idea was to develop the film to a specific level of contrast that captured the full range of tones and make appropriate artistic interpretations with dodging and burning during the print-making process. It worked well with the very exposure tolerant sheet films of the day, where each negative was processed individually, but it's mostly of academic interest today since digital sensors don't offer this extended exposure latitude.
Zoom lens A lens which can be adjusted to give a range of different focal lengths. Most lenses in use today are zooms because they're so much more versatile than fixed focal length (prime) lenses – you can adjust the framing without having to change the camera position. The disadvantages of zoom lenses are increased distortion and other aberrations, reduced maximum aperture and greater cost and weight.
Zoom range The difference in magnification offered by a zoom lens and its widest and longest focal lengths. The average kit lens has a zoom range of 3x, so at full zoom objects appear 3x larger than they do when you're zoomed right out. The Nikon P900 has a record-breaking 83x zoom.
1-inch sensor A new sensor size roughly half way between the small sensors in point and shoot digital cameras and the much larger ones in digital SLRs and mirrorless cameras. It’s found in more advanced high-end compact cameras from Sony and Canon, for example, and Nikon used it for its Nikon 1 mirrorless cameras. It’s been adopted by a number of makers as a way of getting better image quality from compact (non interchangeable lens) cameras.
1/2.3-inch sensor This is the smallest sensor size in widespread use for photography. You’ll find it (or sensors of a similarly small size) in smartphones, point and shoot cameras and some bridge and long zoom travel cameras.
1:1 ratio (square) A 1:1 aspect ratio means the width of the image is the same as its height – in other words, it’s square. The square format was very popular in 120 medium format film photography, and it’s popular today on Instagram.
16:9 ratio This is the aspect ratio of full HD and 4K UHD video and it’s been widely adopted as the aspect ratio for domestic TVs and computer monitors. The 16:9 ratio means that the picture is 16 units wide by 9 units high. These units can be anything from pixels to centimetres to inches, but the point is that the ratio between them always remains the same at 16 wide to 9 high.
16-bit image 16-bit images, which contain detailed color data for the red, green, and blue channels, are derived from RAW files. They're superior to 8-bit images in terms of withstanding significant image manipulation. However, their larger file sizes can strain storage capacity and slow down transfer speeds, and not all software can edit them.
14-bit RAW The ‘bit depth’ of RAW files is a factor in the picture quality they can produce, so this is a selling point for advanced digital cameras. Some cheaper models can only shoot 12-bit RAW files, but while this sounds like a small difference, the extra bit depth potentially offers 4x the image data so 14-bit RAW files are a worthwhile benefit, especially if you want to process photos heavily later.
12-bit RAW RAW files are captured at a greater ‘bit depth’ than regular JPEG images, which makes them much more resilient for editing later. Basic cameras tend to shoot 12-bit RAW files, which are adequate, but arguably not as good as the 14-bit RAW files captured by more advanced/professional cameras.
1/2.3-inch sensor This is the smallest sensor size in widespread use for photography. You’ll find it (or sensors of a similarly small size) in smartphones, point and shoot cameras and some bridge and long zoom travel cameras.
1-inch sensor A new sensor size roughly half way between the small sensors in point and shoot digital cameras and the much larger ones in digital SLRs and mirrorless cameras. It’s found in more advanced high-end compact cameras, and Nikon uses it for its Nikon 1 mirrorless cameras. It’s been adopted by a number of makers as a way of getting better image quality from compact (non interchangeable lens) cameras.
3:2 ratio The 3:2 aspect ratio is used by three main sensor sizes: the 1-inch sensors in some higher end compact cameras, APS-C cameras and full frame cameras. The width of the photo is 1.5 times its height. This is the aspect ratio used by 35mm film.
360 camera 360 cameras create fully immersive video that extends in a full sphere around the camera position, which is usually stationary but could also be mounted on a skydiver’s helmet, for example. There are two ways of working with and watching 360-degree video. One is to use the video as raw material for creating a regular rectangular video, but with the freedom to pan around through a full 360 degrees during the editing process as you choose your viewpoint or create your own ‘panning’ shots. Another is to distribute the 360 video as-is using a suitable display system so that viewers can explore the scene on their own, choosing which direction they want to look in.
35mm camera 35mm film cameras, initially designed for the film industry, remain popular. Full-frame digital cameras with 36 x 24mm sensors are their direct counterparts.
4K video 4K video is a catch-all term for video with a horizontal resolution of around 4,000 pixels. It can include 4K UHD (3,840 x 2,160 pixels) and Cinema 4K (4,096 x 2,160 pixels).
4K UHD The latest consumer video standard, with a horizontal resolution of 4,000 pixels or thereabouts. 4K video is appearing on an increasing number of cameras and even smartphones, and 4K TVs are gaining in popularity. Strictly speaking, the dimensions for 4K video are 4,096 x 2,160 pixels and the aspect ratio is slightly wider than the 16:9 standard for HD video. In fact, what most makers and users are referring to is UHD video at 3,840 x 2,160 pixels, which does have a true 16:9 aspect ratio.
4:3 ratio This is the aspect ratio used by many camera sensors, including smartphones, point and shoot cameras, Micro Four Thirds and medium format cameras. It’s less ‘wide’ than the 3:2 format used for 35mm film, APS-C and full frame cameras.
5-axis stabilization The latest kind of image stabilisation technology, where the camera’s sensor can be tilted or shifted on 5 axes to counter a much wider range and types of movement than regular lens-based image stabilisers, and it’s a particular advantage for video, where these additional movements can pose problems during handheld filming. 5-axis stabilisation used in the Pentax K-1 full frame DSLR, Olympus OM-D mirrorless cameras and the latest Sony A7-series compact system cameras.
6K video 6K video has a horizontal resolution of around 6,000 pixels, or 50% more than 4K video. It’s now starting to appear on some mid-range video cameras, but is used mostly for capturing higher resolution footage for downsampling to 4K (for higher quality) or to allow more leeway for cropping and panning effects in post production.
8K video 8K video has a horizontal resolution of around 8,000 pixels and is still in its infancy, though Canon, Sony and Nikon now all make 8K Mirrorless Cameras.
8-bit image These are photos which use 8 bits of data for each of the red, green and blue colour channels. This is enough to give over 16 million colours – more than enough for photographic images. The JPEG photos taken by digital cameras are 8-bit images.