Bob Walkden <[EMAIL PROTECTED]> writes: > It would be mildly interesting to find out how the word became > attached to 'single focal-length lens'. I suspect it would not have > been used before zoom lenses became common, and that its > photographic meaning was co-opted from 'of highest quality', but > this is just guessing.
And wrong. :-) Once upon a time, it was common to use special sets of lenses for view cameras. You mounted a primary lens, called the prime, on the lens board, and then fixed one of a collection of different secondary (or auxiliary) lenses to the front of the prime lens to select the wanted focal length. They were designed as a kit to work reasonably well this way, and were more cost effective than a collection of complete lenses at the resulting focal lengths -- especially because you got away with a single shutter, in the prime lens. -tih -- Tom Ivar Helbekkmo, Senior System Administrator, EUnet Norway www.eunet.no T: +47-22092958 M: +47-93013940 F: +47-22092901