Jupiter 8 in Leica screw mount has small body which is perfect to be attached in my Sony NEX
As you can see on left, If We don't see front lens it looks like Leica :D
In fact this lens is copy of Carl Zeiss Sonnar 50/2 for Contax rangefinder.
Many people say about Russian copy of Zeiss, almost same with the one being copied. This conclusion, I believe is true including Jupiter 8.
There are some Jupiter 8 variants according to Sovietcam, this lens code name is PT3030. Seems to be an earliest version of the regular Jupiter-8 lens. Released by KMZ in 1951-1960
This lens isn't razor sharp wide open, I'd choose my yashica ML 50/2 for that purpose, somehow I like its character
Someone on photo.net (2002) even said that this lens is Lens Bargain of the Century