I'm having the exact same problem with a 3rd-party lens I just bought.
Vivitar "Series 1" 70-210 f2.8-4 lens. When in "Av" mode, it consistently
overexposes by at least a stop. When in full manual (hit the AE-L) mode the
exposure is dead on. My first thought was that it could be a slow/sticky
aperture, but it *seems* to be moving fast-fast-fast, so I'm not 100% sure
where the problem is yet. :-(
Just out of curiousity - what lens is this that you are having problems with?
I think that the aperture ring on lens mechanism is a bit
different than the A-lever. It's possible for one to be out of
calibration and the other not... in other words, the A-lever is opening
too far (by about one stop). When you go to manual with AE-L, it stops
where the *ring* on the lens tells it to stop and meters on the result.
-Cory
--
*************************************************************************
* Cory Papenfuss *
* Electrical Engineering candidate Ph.D. graduate student *
* Virginia Polytechnic Institute and State University *
*************************************************************************
