I am using a 50mm fixed on the 5D III. I will take a about 100 images and then I get an over exposed image. Then I take a few more and I get another over exposed image. I have tried the eraser trick to clean the senor on the lens. Any other suggestions, hints, anyone else have this problem?
I haven't read any similar complaints at the forums I frequent but it does sound like either a lens problem or a communication problem between the body & lens. There are however several threads about issues with sharpness when using the 50 f1.2 L . Even the 50 f1.4 seems to get it's share of sharpness / build complaints.
Do you have something like "shadow priority" on?(as opposed to the Highlight tone priority)