A lens with a fixed focal length - its field of view cannot be changed. At least, not without the addition of supplemental lenses or teleconverters.
Generally, prime lenses are lighter, sharper, cheaper and of higher optical quality than zoom lenses, since its easier to build a prime lens than a zoom. By tradition, common prime lenses used by 35mm cameras are lenses with 28, 50, 85, 100 and 135mm focal lengths.
cf. focal length, teleconverter, zoom lens.
Entry last updated 2002-05-09. Term 962 of 1487.
Previous term: prime focus.
Next term: print.