Helios 77 1.8 / 50mm
MS (MC) Helios 77M 1.8/50mm, provided by par Alexey. Received on April 9th, 2009.
This lens has no factory logo. This is the case with all Helios 77M that I saw on the Internet. The Helios 77M-4 bear the logos of Valdai or Vologda factories. There also exist Helios 77K-4 for K-mount cameras.
MC Helios 77M-4 1.8/50mm, bought by Christophe on leboncoin.fr with a Zenit ET. Received on July 31st, 2009.
This lens is mechanically identical to 77M. Without other indication, I suppose that the optical formula is slightly different (or it was renamed "-4" to look like the name of the Helios 44M-4 sold at the same time) The marking is slightly different, perhaps they were not made in the same factory.
MC Helios 77K-4 1.8/50mm bought by Christophe, in Irina's parcel received on March 6th, 2010.
The user manuals of Zenit Automat indicate that they are delivered with a Helios 44K-4 or with a Helios 77K-4. In fact, it is very difficult to find a 77. This one, sold alone, had probably never been mounted on a camera: the bayonet had a machining default (I had to file it) and did not fit in any body!
Tests: Please note that these tests were made with the means at hand, not in a "scientific" way. See here.
The optical formula seems to be an evolution of that of Helios 44, the slightly different rear group allowing to go down to 50mm. The result is a little disappointing. But if you use this lens on a digital camera with APS-C sensor, you get a field angle close to the one of a 85mm on 24x36. And as it is very soft, it might make an excellent portrait lens.