Hey folks,

I've got a Crown with top-mount rangefinder and the Xenar 135mm. The rangefinder seems quite accurate compared to the ground glass, but the Xenar is quite soft in the corners. I'm thinking of replacing it with a more modern 135mm (possibly a Fujinon-W). Assuming the actual focal lengths of the two lenses differ by a few mm, will I really need to make a new cam for the new lens, or can I eliminate most of the error just by resetting the infinity stops? Or will a difference of 2-4% show up as focusing error much more readily than I'm assuming? (FWIW, I don't print any larger than 16"x20")