KMZ MC Zenitar-M 16mm f/2.8 Fisheye

One hundred and eighty degrees, measured from one corner of a 24x36 frame to the opposite corner. That number is the reason this lens exists. Across the width and height of the frame it takes in less, so this is not a hemisphere, but the diagonal reaches far enough to catch your own feet when you aim at the horizon. The optical design went through GOI as project Zodiak-13, KMZ in Krasnogorsk built it, and the plant still lists it in M42, Nikon F and Canon EF versions.

The count is 11 elements in 7 groups, though one is a flat, clear plate screwed in at the very back. Leave it there. The lens was computed with that plate in the light path; take it out and you are down to 10 elements in 6 groups and a design that is no longer corrected as intended. Something always has to occupy the rear 26.5mm thread, either the compensator or a filter in its place. Up front there is no thread at all, only a domed front element.

What it draws is a true full-frame fisheye, not a rectilinear wide. A straight line passing through the center stays straight. Every other one bows outward, so a horizon across the middle sits flat while the same horizon near the top edge curls into an arch. As with most fisheyes, expect the center to hold up best wide open and the corners to benefit from stopping down. Outdoors the sun lands inside the frame constantly, and the multicoating can only do so much against a bare sun, so tuck it behind a branch or a roofline.

Handling is ordinary Soviet M42. Six blades run from f/2.8 to f/22 on a pin-actuated automatic diaphragm, so on a body with a pin pusher you compose at full aperture and the blades close only as the mirror rises. It focuses to 0.3 m and weighs about 310 g. Focusing it by eye gets old quickly. Set f/8, line the infinity mark up with the f/8 depth-of-field index (about a meter on the scale), and roughly half a meter to infinity is sharp. That is what suits it to working close and quickly, in a room too small for any other lens or a meter from a skater coming off the ramp.

The weakness is the look. A roll of bent horizons gets tiresome by frame twenty, and a picture whose only idea is the distortion reads as a novelty. Tip the camera even slightly and the verticals in a room start leaning off in different directions. It works best held dead level, with the subject almost close enough to touch. The domed front glass is the other worry. It sits exposed, and with no front thread there is no clear filter to put in its way, so the cap goes back on between frames.

Rear filters are where the lens gets practical. A yellow or orange for black and white, or an ND when you want a wide aperture in hard sun, screws in where the compensator was, and Zone Light Meter folds that filter factor into the reading so the correction is already in the number you set. The usual cross-shops are the Peleng 8mm, which records a circle inside the frame, or a used Nikkor 16mm fisheye at considerably more money. Against that Nikkor, the Zenitar is the inexpensive road to the full-frame look, and a fair test of whether a fisheye earns a permanent place in your bag.