Hello, I own a 5D Mark II and just got from Hungary a good looking Flektogon 35mm f/2.4. the lens is in good condition, no sign of use except a few dusts in the elements. My main concern is that I don't know where the problem is coming from, is it from the lens itself or from my M42 Adapter? 1- The infinity focus (when I do it looking in the viewfinder) is showing at the 3 Meters on the lens, slightly before the infinity symbol. can it be an adapter Issue? 2- at F/8 and before, the side of my pictures are looking blurry, the center is insanely sharp but on the side, when focussing to far distance, I find it not sharp at all, see the examples. I don't have this concern when focussing to near planes, like doing portraits. This is particulary annoying when doing landscape photography!! CROP CENTER CROP SIDE FULL: http://raphael-lacoste.com/forums/Photography/estrie_full.jpg Do you have any Ideas and opinions? thanks!