Archived posting to the Leica Users Group, 1998/05/01
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]At 06:52 PM 5/1/98 -0400, you wrote: >passing the edge of the diaphragm increase. The conjoint effect of both >factors results in maximum sharpness when the lens is stopped down two or >three stops from maximum aperture. For an F2.0 lens, this would be about F4.0. That depends on the lens. The Leica 280 f/4 apo telyt is at optimum aperture wide open. It's diffraction limited, according to Leica. The 180 2.8 Elmarit (second version) is optimum at f/4. Each lens is unique in it's characteristics. No rule of thum can cover all lenses. Leica lenses seem to need less stopping down than most other lenses in my experience. ========== Eric Welch St. Joseph, MO http://www.ponyexpress.net/~ewelch Maintenance-free: When it breaks, it can't be fixed