Puts, the 50mm, 90mm and 135mm Elmarit R lenses are very close to their M equivalents in optical design (135 is identical if I understood correctly), but because of automatic aperture they have only 6 or 8 blades in the aperture.
The other summicrons (50mm and 90mm) are very good too. Hard to explain, but when it works it really do.
It's like the trees along the edges is fighting to re-enter the image somehow. (PS! Exif is wrong due to use of adapter. This I did of my daughter a couple of days ago: The 35 R Summicron is the most difficult lens I own, and it stays on my camera 90% of the time The question for me is not how sharp a lens is, or how soft it is, but rather how a lens is sharp, how a lens is soft, and how the transition between the two is handled. But then again, when I do landscapes, and get the soft corners and edges, I'm at peace with it, I know they are just out of focus, the lens is not to blame, but my way of using it. It's a lens for very specific tasks, not suited for landscape. But this can be played with, and I just love it. Focused at 1.5 meters, the corners are extremely sharp at infinity! When focused at infinity, the edges and corners are way beyond. I have read somewhere that Leica calls this a "lens for journalism". But then none of them have the bokeh rendering out of focus. Not one of them is anyway near the Leica 35mm in center sharpness and contrast, but almost all of them are better at edge and corner sharpness. I have tested all off them multiple times, each time I bought a new lens. The last lens is the only one I have now. I have had many 35mm's for my Canon 5DII Canon 35mm f.2.0, 24-70 Canon L, 35mm 1.4 Samyang, Leica R 35-70mm f.4.0, Leica R 35mm Summicron.