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 […]
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.