To Juhani's question, here are the test shots I made last summer with a small sample of my FSU lenses. I like to use such lenses on the XE-2 because, due to the smaller size of the sensor, you are only using the central portion of the lens coverage, so the rendering is quite homogeneous. My benchmark is a line of 50's/60's Canon LTM39 lenses (from 19 to 135mm) which are astounding, and the FSU lenses of similar vintage are really on par with them (actually Canons are a tiny-tiny bit better, but hard to see, and their market price is 5- to 10-fold !) ; interestingly, and may-be contrary to the legend, the FSUs perform better than the Leica lenses of similar vintage in my inventory. I did not try 35 nor 90mm. First a Jupiter 3 : http://www.ussrphoto.com/UserContent/832018_DSCF9396_red.jpg The post-war FED Industar 22 I tried is clearly not as sharp at infinity (may-be a manufacturing flaw preventing it from quite focusing at infinity ?) ; did not try an I-50 : http://www.ussrphoto.com/UserContent/832018_DSCF9397_red.jpg But the same lens does quite good at short distance : http://www.ussrphoto.com/UserContent/832018_DSCF9256_corr_red.jpg Back to my Auvergne landscape, if you like to see wider, here is the Orion 15 (28mm) : http://www.ussrphoto.com/UserContent/832018_DSCF9390_red.jpg And, last but not least, a Jupiter 11 : http://www.ussrphoto.com/UserContent/832018_DSCF9388_red.jpg
Is there much difference in the edge performance of the different Canon Vs FSU VsLeica lenses. I presume there is, but most subjects aren't at the edge of the photo so it's not too important.