The Jupiter-12

Even though this lens is one of the optics that made the Russian lens manufacturing industry famous, it isn't a Russian design. The Jupiter-12 is in fact a copy of the pre-war Carl Zeiss Biogon 3.5cm f/2.8 for the Contax. After World War II, when the Soviets transported large parts of the Carl Zeiss factory to the homeland, the cameras went to Kiev and the lenses to Krasnogorsk. Zavod Arsenal started producing Contax copies under the Kiev name, and KMZ started producing copies of Zeiss lenses. At first Arsenal and KMZ used original Zeiss parts, but when they ran out they started making their own. When there were no more original Zeiss Biogons to produce the BK (Biogon-Krasnogorsk) 3.5cm f/2.8 with, KMZ fired up its own production line. That's how the Jupiter-12 came to be. First in Kiev-Contax mount, but when KMZ started manufacturing its own Leica copies, also in L39.

KMZ produced the Jupiter-12 between roughly 1950 and 1960. After that, production was shifted to KMZ's sister factory LZOS in Lytkarino. Its J-12's were first finished in chrome, but around the mid-seventies were replaced by the classic black enamel version. That one probably stayed in production till around 1980 when the Zorki-4K was abandoned.

Although I have to admit I've never done any representative testing with my Jupiter-12, the consensus is that it's an excellent lens due to its non-retrofocal design. Lenses designed in that manner tend to have more severe vignetting problems than retrofocal lenses, but also much less problems with distortion and sharpness. The Jupiter-12 is said to be an excellent optic, sharp and contrasty and low on distortion, that demonstrates the Russian (?) excellence in lens design.