Categories of Lenses

Lenses can be categorized by their intended purpose—general photography, macro photography, and so forth—or by their focal length. The range of available focal lengths is usually divided into three main groups: wide-angle, normal, and telephoto. Prime lenses fall neatly into one of these classifications. Zooms can overlap designations, with a significant number falling into the catch-all wide-to-telephoto zoom range. This section provides more information about focal length ranges, and how they are used.

Any lens with an equivalent focal length of 10mm to 20mm is said to be an ultrawideangle lens; from about 20mm to 40mm (equivalent) is said to be a wide-angle lens. Normal lenses have a focal length roughly equivalent to the diagonal of the film or sensor, in millimeters, and so fall into the range of about 45mm to 60mm (on a full-frame camera). Telephoto lenses usually fall into the 75mm and longer focal lengths, while those from about 300mm-400mm and longer often are referred to as super-telephotos.