Quote Originally Posted by eddym View Post
Huh? Howzzat work? I agree with the brightness part, but how can a focusing screen change the apparent dof on the screen?
As for the exact optical reasons, I do not know. But I know it has something to do with the design of the little fresnel (or whatever it's called) pattern cut/ground into the screens. They are designed to focus and optimize the viewfinder image for f/2.8 or slower lenses, because they figure most people using AF cameras are using zoom lenses.