Years ago I had the use of an R-3 MOT with the Summicron. I now have two of the 50mm Nikkor Hs, and comparing slides made with the two lenses, there is a slight difference in contrast and color balance; the Nikkors are reputed to have some barrel distortion but not having taken pictures of brick walls and test charts, I can't see it. There is a difference between the Summicron and the Nikkors but you have to work to see it. Those Nikkors are d@mn nice lenses!
Originally Posted by momus
The Leicaflex SL2 was the last 'echte' Leitz reflex, the R3 was actually based on a Minolta.