Helios-44

Testing a Helios-44 f/2 lens, using it on a Canon EOS 30D camera.
This lens is a Soviet copy of the Carl Zeiss Biotar. Millions were manufactured and there are many different versions, including M42 screw mount and Pentax K mount. It is 58mm focal length. Maximum aperture is f2, minimum f16. It is considered a very good lens and it is not hard to find. The '44' is just a model number and has nothing to do with the focal length. My early version has a 49mm filter size; in later versions this was changed to 52mm.
When I first used one of these lenses, it was an auto type with a pin which communicated with the companion Zenit camera to shut down the aperture from wide open (for focussing) to the selected detent. This earlier version is a preset type with 2 aperture rings. You set the desired f stop with one ring, and then use the other to open wide for easier focusing and composition. When ready, you turn the second ring clockwise and it closes to the pre selected aperture.