Depth of field is the near to far sharpness in your pictures. A picture with shallow depth of field has only the main subject in focus, and everything in front of it and behind it is blurred. The opposite is a picture with deep depth of field, where everything is sharp from right up close […]
Focal length is an indication a lens’s magnification or angle of view 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. This is necessary because cameras come with different sensor sizes, so the angle of view of a lens changes according to the camera's sensor. Today, photographers still talk about focal length in 35mm camera terms, using the focal length to characterise lens types – so a focal length of 28mm or shorter is a wideangle lens, a 35mm is a 'moderate wideangle', a 40-60mm lens is a 'standard' lens, and a lens of 70mm or longer is a telephoto (you get 'short' telephotos, medium telephotos, long telephotos).
Lenses are always identified by their focal length. It’s not just a physical measurement, it’s an indication of the type of lens it is, for example, a wideangle lens, standard lens, telephoto and so on. In other words, the focal length of the lens gives you an indication of its angle of view. Or at […]
The advantage of interchangeable lens cameras like DSLRs and mirrorless cameras is that you can change lenses for different kinds of photography. There are many different types of lenses, often with specific names. Lenses are usually characterised or grouped by their focal length. It might be more useful to use their angle of view instead, […]
Camera shake is blur caused by camera movement during the exposure. It happens with indoor shots or outdoor shots in poor lighting or at night, when the low light levels mean the camera uses a longer exposure and hence a slower shutter speed. The slower the shutter speed, the more likely it is the camera […]