This is not unusual, it is in fact, common that different lenses and camera combinations result in different exposures. Sometimes it's the camera's shutter at certain speeds, and sometimes it's the lens' particular certain aperture not being exact. The cumulative effect of the shutter and aperture errors can be significant, as you found out.
Advanced B&W books often suggest establishing film speeds and development times by testing every lens individually at each aperture on the same single camera, and finding where the "correct" exposure is by bracketing and establishing where base + fog is on the film verses maximum density. Even then, you've only established it for a single lens and camera combination, and it's also quite possible that your camera/lens would perform differently in different auto exposure modes, as well as in manual exposure. I find this to be a pretty impractical approach to 35mm shooting, but certainly valid for larger formats. In a practical sense, you've taken the first step to realizing that you have some variables that cumulatively add up pretty significantly. If I were you, I'd "waste" a few rolls on a gray card, maybe in the exposure mode you use most often and see which lenses and apertures perform how, and just file that information away in your brain for the future in case you feel the need to want to compensate for it. I would think the biggest factor in deciding afterwards whether it's an issue or not might be the type of film you use most often. With color negative film, it's probably not an issue at all. Thanks, Ed http://lightandsilver.com > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED]] On Behalf Of Brent Hutto > Sent: Saturday, December 01, 2001 8:44 PM > To: [EMAIL PROTECTED] > Subject: Exposure Difference: SMC-A 50/2.0, SMC-M 135/3.5, SMC-M 200/4 <snip> > The bad news is that the exposures were not the same. The shot at <snip> - 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 .
