Quick Tips: Normal Focal-Length Lenses

A normal focal-length lens, also called a standard focal-length lens, approximates what the human eye sees. One of the greatest modern photographers, Henri Cartier-Bresson, who described the camera as “an extension of my eye,” almost always used a normal lens. The angle of view of most of his images is about the same as what the eye can see clearly from one position, and the relative size of near and far objects seems normal.


A lens that is a normal focal length for one camera can be a long focal length for another camera. Film size determines what will be a “normal” focal length. The larger the size of the film format, the longer the focal length of a normal lens for that format. If the focal length of a lens is about the same as the diagonal measurement of the film (broken line), the lens is considered “normal.” It collects light rays from an angle of view of about 50°, the same as the human eye.