Flektogon M42 on 5D Mark II

[elrafo]

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!

 

[Garbz]

Does the adapter have a glass element? If so it could be to blame. From what I could scrounge up on the net the Flektagon 35mm f/2.4 should be a sharp lens all round.