How do I focus the variable diopter on my PME 45 & 90?
Remove the lens from your camera body. Move the switch by the diopter to unlock.
(located below the viewfinder on the PME 45 or to the right of the viewfinder
on the PME 90).
Look trough the viewfinder at a light solid colored wall and
rotate the eyecup right and left until the cross hairs (2 vertical & 2
horizontal lines) in the center of the focusing screen in the viewfinder appear sharp and in focus.
Next re-attach the lens, and lock the diopter in place. You are ready to go.