At 13:34 09.11.01 +0100, you wrote: >On Fri 2001-11-09 (11:30), Frank Wajer wrote: >> on kmp.bdimitrov.de I saw the specs of the 200 f2.5 lens. It says that the >> filter >> ring is 77mm, but this means that the lens cannot be f2.5, as that would >> mean >> a minimum 80mm filter ring! >> >> Can anyone explain?
Most likely the focal length is not 200 mm, but something like 185 or 190mm. Then you would be fine. Often the expressed focal length does not quite match up to actual focal lenght (this does not make a lens inferior). Having the f-stops correct is more important! By the way, the 135mm lenses show considerable variation in actual focal length as well, I read somewhere that some guy found values between 115 and 139mm (this comparison included different manufacturers). Knut - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
