KMZ Zenit-EM

f/2 on a Helios-44M is a dim, shallow place to focus, and a Zenit-EM lets you stay there. The finder sits at full aperture while you find someone's eyes. Press the release and the lens closes to whatever you set on the ring, holds there as long as your finger stays down, and opens again when you let go; the view comes back after the mirror's brief blackout. The Zenit-E next to it on the flea-market table works differently. With its preset lens you focus wide open, turn a second ring down to the taking aperture, then frame through a darker screen before you fire. Plenty of people shot portraits and street pictures that way for years. The auto diaphragm simply makes the EM much quicker on anything that moves.

Underneath, it is still a Zenit-E, which made it an easy update for Krasnogorsk. Same M42 screw mount, same cloth focal-plane shutter, same heavy body. KMZ added the automatic stop-down linkage for the Helios-44M and other M42 auto lenses, plus a separate shutter release, and then built 979,140 of them, nearly all between 1972 and 1984. A good share left the country under other names: Kalimar SR300, Cosmorex SE, Revueflex-EM, Cambron-EM and Diramic R-2. Check the prism before you assume you have found something rarer. There were also Moscow 1980 Olympic editions, in chrome and in black.

The meter is where the EM shows its age. A selenium cell sits above the lens, a calculator dial sits on the body, and neither one is connected to the shutter or the aperture. You read the needle, carry the number over to the dial, and set both controls by hand. No battery is involved, which people like. Selenium does lose sensitivity with age and light, though, so before trusting a 40 or 50 year old cell, compare it against the Zone Light Meter app across a few scenes. If it reads off or not at all, take incident or spot readings from the app instead. If it tracks, keep it as a quick cross-check.

The shutter range is the real limit: 1/30 to 1/500 plus B, with flash only at 1/30. Nothing sits between B and 1/30, so a dim interior means handholding at 1/30 or a tripod and a counted Bulb exposure. At the bright end, sunny-16 with ISO 400 film already puts you around 1/500 at f/16, which is about as far as the body and a Helios will go. Fill flash in daylight at 1/30 rarely works out. Load ISO 100 or 200 and most scenes fall in the middle of the dial.

Everything else is mechanical and simple to service. The wind stroke is long, the mirror comes down with a solid clunk, and you notice the weight after an afternoon on a strap. It is often among the cheapest M42 bodies on the used market, and it works the Helios-44M's auto diaphragm properly, which is the main reason to pick it over a preset-lens E. If you want a meter that reads through the lens on the same mount, a Praktica MTL is the obvious body to cross-shop.

People who keep the EM do so for the lens on the front and a shutter that runs without any battery at all. The meter, if it still works, is a bonus.