Archived posting to the Leica Users Group, 2001/05/16
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]In a message dated 5/16/01 11:22:00 AM Eastern Daylight Time, icommag@toad.net writes: << why are cinema zoom lenses so much faster than for still cameras? I have three Angenieux cinema zooms, all quite fast. For example my 9.5mm to 57mm is a f1.9, my 16mm to 44mm is f1.3. >> How large is the film area these lenses are required to cover? Answer to your question is your lenses are corrected to cover a much smaller image circle than the 35mm format - 24X36. It's far easier (and cheaper) to compute a lens, whether fixed focal length or zoom, to correct aberrations to an acceptable level in a small image circle than a large one. Seth Rosner LaK 9