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.

AA batteries

These 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.

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.

5-axis stabilisation

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.

4K video

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.

16-bit image

These are photos with 16 bits of data for each of the red, green and blue colour channels. These aren’t created directly by the camera, but you can generate 16-bit images from RAW files and they withstand heavy image manipulation better than regular 8-bit images. The file sizes are much larger, though, which puts more pressure on your computer’s storage capacity and slows down file transfer speeds, and not all software can edit 16-bit images.

1.5-inch sensor

A unique sensor size used by Canon in its top PowerShot compact camera, the G1 X II. It’s just a little smaller than the APS-C format used by most DSLRs and larger than the 1-inch sensors used in other high-end PowerShot models, so it gets close to the quality of a good interchangeable lens camera.

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.

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.