The Jupiter-12 35 mm f/ 2.8(Russian: "Юпитер") is a wide-angle lens with an iris aperture and a single-layer coating for rangefinder Zorkiy type cameras with the m39 Leica screw-mount (LSM). It was also produced in a bayonet variant for Kiev rangefinder cameras, the Contax I-III system (CRM).
Its optic scheme was borrowed from the Carl Zeiss Biogon 2.8/35. Initially, it was named BK-35 (Biogon of Krasnogorsk). Besides the Krasnogorsk mechanical works (KMZ), the Jupiter-12 was produced at the Lyktarinsk Optic Glass Factory (LZOS).