MC Helios-77M 1.8/50 is a very interesting lens. Firstly, letters «MC» mean, that it has a multilayer blooming.
Secondly, I want to pay your attention that there is no manufacturer’s name on my MC Helios-77M 1.8/50. It’s probably an export variant of lens. Besides, I consider, it’s a copy or rework of MC Helios-77M-4 1.8/50. If somebody has an information about it, please, write it in the comments.
Lens has a great sharpness and takes the back- and sidelight without any problems. I think, it’s one of the best Soviet lenses. I recommend you to buy it or MC Helios-44M-4 1.8/50, if you will find it anywhere.
Focusing is smooth. The focusing ring rotates by 180 degrees, while front lens doesn’t move and the trunk of a lens extends by 1cm. Minimal distance is 45cm. The lens has a focusing distance scale for the exact focusing control and a depth-of-field scale. The focusing ring is metallic. The lens is well-build at all, but the carriage near the front lens is plastic on my model and has a backlash. Lens use diameter 52mm for the front light filter. The body carriage is made in the typical for the last Helios lenses colors.
You can set the aperture from F/1.8 to F/16. The blade’s quantity is 6. That’s a pity, cause if the lens will have a round multiblades aperture, it’ll be really great. The aperture is blinking, only manual aperture control. By the using on the modern cameras you need to block the aperture to get the manual control.
The serial number of my model is 92029111. Probably it was made in 1992. The blooming has a green shade, i suppose, it differs with MC Helios-77M-4.1 and MC Helios 77M 1.8/50.
MC Helios-77M 1.8/50 is a good wide-aperture lens. It twist the extreme wide shot in the unsharpness zone. I recommend it.