[dave9t5]

This is probably not definitive, but seems like a reasonable discussion of the zenith of Russian premium optics:

 

http://www.camapart.com/camera-and-lens-...ens-review

 

[...] the 1.5 maximum aperture is indicative of lens' ancestry from mid-century Zeiss design [...] and Zeiss crown achievement at the time, the magnificent Sonnar.
[...] it quickly become the dominant design for super-fast lenses of the next two decades. Some popular knock-offs of it included:

• <p style="margin-left:40px;">Jupiter-3 1.5/50, the primary subject of this article;
  
  
  

<div style="margin-left:40px;">The story of the Jupiter (the Roman interpretation of Zeiss.. er, Zeus) is complicated. In the build-up of World-War II, the USSR and Nazi Germany collaborated on a number of issues, including cross-licensing of optical designs. However, Sonnar did not get a chance to surface in the East until the hostilities broke. [...] Krasnogorsk mechanical plant near Moscow (known as KMZ) picked up the designs, the coating technology, a number of lens parts and intact chunks of Schott glass, and set up the manufacturing. It was actively helped by key Zeiss engineers, so by early 1950s the production was in full swing. The original German glass did not run out until 1954; after that, however, most designs were recalculated by KMZ to accommodate for domestic types of glass.
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