MC Helios-77M-4 1.8/50 is a quite rare and good high-aperture prime lens. In it’s time it was a qualitative standard lens for some roll-film cameras «Zenit». Now you can find MC Helios-77M-4 1.8/50 on the flea market, it can be used as a good manual lens for modern cameras.
MC Helios-77M-4 1.8/50 is well-built. The focusing ring has no rubberized inserts and rotates by 200 degrees. Manually focusing doesn’t make any difficulties. The front extended part of the body doesn’t rotate by the focusing. It proceeds by means of movement of all lenses block.
It also has several disadvantages: aperture’s blades are not blackened, it can lower the contrast. Besides, there are only 6 blades. So, the nuts appear easy on the covered apertures in unsharpness zone. MC Helios-77M-4 1.8/50 is equipped with standard blinking aperture, which works in automatic mode on the majority of cameras with pilot thread M42х1/45,5.
Main technical characteristics:
1) Name: MC Helios-77M-4 1.8/50 M52x0,75 91060951 with VOMZ logo.
-M42x1/45.5 — a widespread pilot thread ‘M42′.
-Manual focusing only.
-Aperture control ring, semi-automatic aperture control by means of an aperture ring and an aperture pusher of cameras for which it is available.
-MC — multilayer enlightment.
-The lens suits for full-frame format cameras.
3) Front filter diameter — 52mm.
4) Focusing distance — 52mm. Equivalent focal length for cameras with sensor type APS-C is about 75mm.
5) Zoom — 1x
6) Made for moving-film cameras with shot size 36mm X 24mm.
7) Aperture’s blades quantity — 6 rounded blades. Blades form a hexagon of approximately correct form. On intermediate value between F/1.8 and F/2.8 they form a hexagon with small jags. Blades are opaque metal, not blackened.
8) Marks — Focusing distance in meters and feet. Depth-of-field scale for values F/4, 8, 11, 16. Aperture values for F/1.8, 2.8, 4, 5.6, 8, 11, 16. The ring has on one intermediate fixed value between the specified couples of numbers (between F/11 and F/16 is no intermediate value).
9) Aperture — From F/1.8 to F/16.0, it is regulated by an aperture ring, there is no switch of a method aperture work on a lens.
10) Minimal focusing distance — 0.45m, maximum coefficient of increase is 1:6.3.
11) Weight — about 250g.
12) Optical arrangement — 6 elements in 4 groups.
13) Blend — is twisted in the forward light filter, marking of an original blend isn’t found.
14) Manufacturer country — Russia.
15) Period — several years about 1990, the exact period of production is unknown.
It is easy to use lenses with a pilot thread of M42 on the modern digital cameras, for this purpose it is enough to pick up the correct adapter. I used this lens on the full-frame mirrorless camera Sony A7 with M42-NEX adapter without any problems.
MC Helios-77M-4 1.8/50 is quite sharp in the shot center even on F/1.8, but on the edges it’s worse. The lens shows a very high sharpness on the covered apertures. Vignetting is noticeable on F/1.8.
Lens show good contrast by working without the back light. Unfortunately, despite MC optics, a lens poorly works in back light, giving a large number of flares, patches of light and ‘rainbows’. MC Helios-77M-4 50mm 1:1.8 woks in back light much better. Highlight of MC Helios-77M-4 1.8/50 is unusual twisting of a distance shot in an unsharpness zone, thanks to it the lens has an interesting bokeh.
So, MC Helios-77M-4 1.8/50 is an interesting lens, which can be a good creative tool for photographers. But is’ worse than MC Helios-81H 2/50 because of weak work in the back light.