Carl Zeiss Distagon T* 28mm f/2

Screw a Contax/Yashica adapter onto a Sony body and you are holding a lens that became a favorite to adapt once shooters rediscovered Contax Zeiss glass. Before that it lived on Contax bodies, the RTS and the Aria and the 159, made from 1980 into the early 2000s, spanning much of the Contax/Yashica system's life. It is a Distagon, Zeiss shorthand for a retrofocus wide. A 28mm has to sit far enough from the film to clear an SLR mirror, so the design runs backward, a big front group throwing the image plane well behind the last element. Doing that at f/2 without the corners collapsing is the hard part, and this is what Zeiss built to pull it off.

Wide open it is sharp in the center with the microcontrast people call pop, the in-focus plane sitting slightly proud of everything behind it. Stop to f/4 and the corners catch up. By f/5.6 to f/8 it is even across the frame and genuinely excellent. Colors come out deep and well separated, with the kind of contrast that holds even in flat light, and the T* multicoating fights backlight better than most fast wides of its generation. Point it at a streetlight and you get a tidy flare, not a washed frame. The cost is some field curvature wide open and visible vignetting at f/2 that mostly clears by f/2.8.

This is a reportage focal length. 28mm is the length you walk a room with, close enough to put a person in their space without the cartoon stretch of a 24. Documentary and street shooters reach for it, anyone who wants one fast wide on the body all night. Some examples carry Made in West Germany, others were built in Japan under Kyocera, and the German ones pull a collector premium that has more to do with the badge than the glass. Prices climbed hard once the mirrorless crowd found them and have stayed up. People still cross-shop it against the Distagon 25mm f/2.8 in the same mount and the 28/2 SLR primes from Canon, Nikon and Olympus.

The honest weakness is those wide-open corners and the field curvature behind them. Shoot a flat subject at f/2, a brick wall or a landscape with detail running into the edges, and the focus plane dishes while the corners soften. Stop to f/5.6 and the problem is gone. The other catch is human: nailing f/2 on a 28 by hand, on a dim finder or a magnified EVF, takes practice and patience. When you are working it open in the dark, meter for the shadows you actually want to keep, set Zone Light Meter to f/2, and read the shutter speed it gives you before you trust your eye on the focus.