Archived posting to the Leica Users Group, 2001/11/15
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]Sheeesh. One more thing to worry about. Does this mean in "practical" terms that metering at f1.4 is inaccurate and that metering at f2.0 is more accurate? Therefore you should meter at f2.0 and then you set from that reading your f1.4 shutterspeed? In my case I have a 35mm Summilux (old) and a classic M6. thnx John Fulton Fort Worth > >It is normal. The inherent vignetting of any optical system wide open causes >this effect. It is most noticeable with the Noctilux. See Osterloh's Leica M >book for a well illustrated explanation. > >John Collier > >PS: Try your local library for the book. I might be persuaded to scan the >relevant sections out of my copy if you cannot locate it. > >> From: Ray Moth <ray_moth@yahoo.com> >> >> I've just noticed a peculiarity in the behaviour of the light meter in >> my M6 TTL, using a 50mm Summilux-M lens. If I adjust the aperture from >> f/1.4 to f/2 or vice versa, the meter doesn't register any change, >> whereas a change in shutter speed does register. >> >> For example, if the meter indicates that f/1.4 at 1/500 sec. will give >> the correct exposure, then I would expect f/2 at 1/250 sec. would give >> the same indication but it doesn't; it shows over-exposure, as if I'd >> selected the slower shutter speed but left the lens aperture at f/1.4. >> Conversely, if I started at f/2 and 1/250, a change to f/1.4 and 1/500 >> would indicate an under-exposure. The lens aperture selector seems to > > function properly. Has anyone else experienced this problem? - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html