I have one mounted in a copal 3 and something had to be trimmed, according to Steve Grimes. I have a few vignetted shots on my web site ( http://www.jamieyoungphoto.com/B&W%2...olios%201.html ) that show the image circle on an 8x20, found in the Madison link, and the Badger Army Ammunition Plant link. It falls off in sharpness after about 8x10. The lense was designed for copy work at around 1:1, and supposedly is great for that, but doesn't work well at infinity. Jim Galli is right.A regular gclaron is a better choice