Quote Originally Posted by jochen View Post
......No external viewfinder can fully take into account the parallax mistake and the variation of the image field caused by fokussing from infinity to close range.
Everybody who wants to compose exactly into the frame should use a SLR with 100 % viewing on the screen like a F 2 or F 3.
Russar MR2 20mm viewfinder is parallax corrected from 1m to infinity. It is very precise in my experience and cover well up to 100%.