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Parfocal Lenses
The Wayback Machine - https://web.archive.org/web/20071007070643/http://www.rogercavanagh.com:80/helpinfo/30_parfocal.stm

 

"Parfocal" means that a zoom lens will not change focus as the focal length of the lens is changed. This is some more information provided by the invaluable Chuck Westfall of Canon US.

Parfocal zooms in the Canon EF lens line-up are essentially limited to the fixed-aperture L-series category and front-focusing zoom lenses.

The current products include: Discontinued lenses in this category include:
  • EF 16-35mm f/2.8L USM
  • EF 17-40mm f/4L USM
  • EF 24-70mm f/2.8L USM
  • EF 70-200mm f/2.8L USM
  • EF 70-200mm f/2.8L IS USM
  • EF 70-200mm f/4L USM
  • EF 75-300mm f/4-5.6 IS USM
  • EF 75-300mm f/4-5.6 III USM
  • EF 75-300mm f/4-5.6 III
  • EF 90-300mm f/4.5-5.6 USM
  • EF 90-300mm f/4.5-5.6
  • EF 17-35mm f/2.8L USM
  • EF 20-35mm f/2.8L
  • EF 28-70mm f/2.8L USM
  • EF 28-80mm f/2.8-4L USM
  • EF 50-200mm f/3.5-4.5 USM
  • EF 50-200mm f/3.5-4.5
  • EF 70-210mm f/4
  • EF 75-300mm f/4-5.6 II USM
  • EF 75-300mm f/4-5.6 II
  • EF 75-300mm f/4-5.6 USM
  • EF 75-300mm f/4-5.6
  • EF 80-200mm f/2.8L
  • EF 100-300mm f/5.6L
  • EF 100-300mm f/5.6

EF zoom lenses with Super Inner Cam focusing, which include most of the non-L zooms introduced from 1990 onwards as well as the EF 35-350mm f/3.5-5.6L USM and the EF 100-400mm f/4.5-5.6L IS USM, are not parfocal.

This information was original posted on the Rob Galbraith Forums on 29 May '03