KMZ Tair-3S 300mm f/4.5 (Photosniper)

Of all the glass that ever came out of Krasnogorsk, this is the one most likely to get you stopped by a park ranger. KMZ sold the Tair-3S bolted to a shoulder stock with a pistol grip and a trigger, a Zenit hanging off the back. It came as the Photosniper kits: FS-3 with a Zenit-ES, FS-12 with a Zenit-12S, plus the FS-122 and FS-412, each with the stock, a hood and a set of filters. Carry one through a car park and expect questions.

The optics are older than the rifle look. D.S. Volosov computed the Tair-3 in 1952, and KMZ kept making the family from the mid 1950s right up to 2005. Three elements in three groups. That is about as simple as a 300mm gets. Even so, the lens alone weighs about 1.4 kg, and that is before the body and stock go on.

On the S version, focusing and the diaphragm release moved onto the stock. Your thumb focuses with a wheel, not a ring. The diaphragm runs on a spring that you cock before each frame, so you compose at full f/4.5, and one pull of the trigger shuts the iris to the preset aperture and then fires the shutter. It is crude next to the pin-driven automatic diaphragm on the Jupiter-21M, but it gets you the same open-aperture viewing. Forget to cock it and the iris is still closed from the last frame, so the finder goes dim and you are focusing at the taking aperture. Close focus is 3 m, which is plenty for a heron on a bank.

Sixteen blades is a lot of iris. Out-of-focus highlights stay close to round through most of the range, and a background well behind your subject at 300mm turns to smooth wash. Wide open you can see colour fringing on hard edges, bare branches against a white sky being the classic offender, and stopping down helps. Keep the hood on every time. An older lens like this can lose contrast quickly when the sun is anywhere near the frame.

Handling is where it bites. The Zenit-ES and Zenit-12S both top out at 1/500, and that is about the slowest speed you can trust handheld at 300mm, even with a stock pressed into your shoulder. On a dull day you are pushing film or reaching for a monopod. The kit filters earn their place for black and white skies, and if you screw a yellow or orange one into the M72x1 thread, add its filter factor in Zone Light Meter so the reading accounts for the light it eats.

Complete kits tend to draw collector interest, while a bare lens is the more common find. People chasing reach on a budget cross-shop it with a Rubinar 500 mirror lens, which is shorter, lighter and longer in focal length but has no iris at all, so out-of-focus highlights turn into rings. The Tair keeps a real diaphragm and a calmer background. It still finds buyers among bird and aircraft shooters, and among anyone who likes the flattened look of a street photographed from a block away. Just remember that the stock which makes it handle so well is also the reason you will think twice before raising it in a crowd.