KMZ Zenit-S

Turn a Zenit-S over in your hands and the giveaway is a small flash socket on the front, with a synchronising lever and its little millisecond scale up by the rewind knob. That pair is what separates it from the first Zenit. The cloth focal-plane shutter, the film path through the base and the M39 screw mount all came across from the original body. KMZ made 232,949 of them between 1955 and 1961, six years of production for a camera whose headline change was a way to fire a flash.

The S stands for synchronised. In the engraving the letter is a Cyrillic C, so collectors often list it as the Zenit-C, and the British import wore Latin lettering and the name Zenith-C. The lever by the rewind knob sets a delay from 0 to 25 milliseconds against its scale. Flashbulbs take a moment to climb to full burn, so you move the lever to some delay for a bulb and leave it at zero for an electronic unit. Then the English manual sets the limit: flash at 1/25 or on B, and nowhere else. With sync only at 1/25, daylight fill flash is awkward, because in bright light you run out of aperture before the ambient exposure is under control. Indoors, with a bulb in a reflector, the arrangement makes far more sense.

You advance the film with a knob. Framing happens through the prism onto a ground-glass screen with no split image or microprism, so focus is judged by eye, and a well-lit subject helps a great deal. There is no meter of any kind. Early bodies run 1/25 to 1/500 plus B; from about 1960 KMZ moved late ones to the standardised 1/30, 1/60, 1/125, 1/250, 1/500 sequence, so check the dial on your copy before trusting an old exposure table. Film goes in from the base, Leica style, and the leader has to be trimmed long. A store-cut leader will teach you that the hard way.

Then there is the mount. It is an M39 thread, yet the flange sits at 45.2mm, the Zenit register, well behind the shorter rangefinder distance. A Leica-thread lens will screw straight on and never reach infinity, an easy mistake to make at a camera fair. You are tied to M39 Zenit glass. That system later gave way to M42, which took over with the Zenit-E family, and the M39 line closed with the Zenit-3M around 1970. If you want an M39 Zenit to shoot every weekend, the 3M is the easier body, thanks to its hinged back and lever wind. The S suits people who want the flash-synced version of the original design.

The top speed is where it pinches. With 1/500 as the ceiling, ISO 400 in full sun already puts you at f/16, so ISO 100 or slower film suits this camera far better and lets you open the lens up a stop or two. Surviving bodies often need a shutter service before the speeds can be trusted, and if you buy in Britain you may well find the Latin-lettered Zenith-C version.

With no meter in the body, a reading from the Zone Light Meter app is how you place exposure on a Zenit-S. Take an incident reading for a portrait by a window, or spot-read the shadows when you want them on a particular zone, then carry the numbers over to the dial by hand, as every owner of this camera has always had to.