Helios-44-2, black lens for SLR camera
58 mm, f/2, M42 mount, s/n 80066117
"Jupiter" plant, USSR

Very good condition. Glass is clear and clean, without any or scratches fungus. Inside there are microspecks of microdust. Focus and aperture rings rotate properly, aperture liimit ring has a backlash. Body has small signs of age and use.

Camera :Zenit B" is not included and shown as an example of mount.

I took test photo with this lens set on DSLR "A-100" via adapter. Test photo is the last one.

This lens was designed at Krasnogorsky Mechanical Plant. This is a representative of vast "Helios-44" family, that was based on German Carz Zeiss Jena Biotar 2/58. Firstly it has a name "BK" - Biotar from Krasnogorsk.
Optical scheme was calculated in 1951 at State Optical Institute. Lens was produced since 1958 till 1994 at three plants: KMZ, BelOMO, Jupiter with four possible mounts: M39, M42, Pentax-K mount, Start. This is one of the most popular lenses in the world.

This version has 8 rounded blades.
When mounted with adapter on Canon, for example, its focal distance will be: 92,8mm (for APS-C), 75,4mm (for APS-H).

Characteristics:
Lens s/number - 80066117
Number of lenses - 6 in four groups, Biotar
Angle of view - 40o
Number of aperture blades - 8
Limit of aperturing - 1:2 (max), 1:16 (min)
Resolving power - (centre/edge) 38/20 lines/mm
Minimal distance of focusing - 0.5 m
Type of thread - M42 mount
Type of thread for the nozzles - 49 mm
Dimensions (mm): 476060
Focal distance - 58,60 mm.
Mass - 222 g
One-layered anti-reflection coating