Zoom lens

A zoom lens is a mechanical assembly of lenses whose focal length can be changed, as opposed to a prime lens, which has a fixed focal length. They are commonly used with still and video cameras, some binoculars and telescopes, and other optical instruments.

References

• Kingslake, R. (1960), "The development of the zoom lens". Journal of the SMPTE 69, 534
• Clark, A.D. (1973), Zoom Lenses, Monographs on Applied Optics No. 7. Adam Hildger (London).
• Malacara, Daniel and Malacara, Zacarias (1994), Handbook of Lens Design. Marcel Dekker, Inc. ISBN 0-8247-9225-4