I have a AV-1 Canon. I look through the eye piece and see black marks. I cleaned the mirrors and eye piece without solving the problem. I've changed the lens and still have the marks. I can't see any marks on the mirrors. If anyone has an idea what is causing this or knows of a good camera repair that can help me, please let me know. Thank you. spank
Sometimes there is dirt or pieces of mirror foam that work their way on top of the focus screen, the inside surface of the viewfinder, or on the pentaprism. Often the only way to get to them is to remove the top plate. Usually, the marks have no effect on the pictures unless they are on the lens itself.
