Quote Originally Posted by BrianShaw View Post
P.S. this is the small and rediculously expensive item that CGW mentioned. I check mine periodiucally to make sure that they are screwed in. They are, indeed, small and rediculously expensive... but the best option in my experience.
I find those stay put if tightened down. The bigger ones for the F3's DE-2+DE-3 finders and the N90s + F100 will loosen almost as fast as the eye cup.