Can Anyone Explain this?

[leica M2 fan]

I have been looking for a Zeiss Sonnar lens for my Kiev 4aM for a while. What is perplexing to me is that I've seen 50/1.5 Sonnar T chrome (40.5) and also 58/f1.5 Sonnar. Do they both fit? What is the advantage of one over the other? Any advice? TIA.

 

[nzeeman]

there were discussions about this 58mm lens - its a mystery 🙂
http://www.rangefinderforum.com/forums/showthread.php?t=45497
http://www.rangefinderforum.com/forums/showthread.php?p=883091

however 50/1.5 is ok lens on kiev i think - i have 50/2 sonnar and it works ok...