Carl Zeiss Biogon T* 28mm f/2.8 G

Stand at the base of a building, tilt up slightly, and shoot. The verticals stay vertical. Brickwork at the far corner of the frame holds the same bite as the center. This is the situation a retrofocus 28 of the same era fumbled, and it is exactly what the Biogon was built to win. Most 28mm lenses for SLRs had to clear a mirror box, which forces a retrofocus design with its baked-in barrel distortion and softer corners. The Contax G had no mirror. Zeiss took the opening and gave it a real symmetrical Biogon, the formula Ludwig Bertele's lineage perfected for distortion-free wide coverage. The result is one of the flattest, most rectilinear 28s ever put on a small camera.

Wide open at f/2.8 it is already sharp across most of the frame, with the extreme corners snapping in by f/4 and the whole field flat by f/5.6. Distortion is essentially nil, the kind of number you usually only see on a view-camera lens. Contrast is high and clean in the classic T* way, color leaning neutral and slightly cool. Flare resistance is genuinely good for a wide of this vintage. Shoot into a streetlight and you get a tidy point of light rather than a wash of veiling. The 46mm filter thread is small and cheap to feed, which matters if you want an ND or a polarizer for that flat architectural work.

Bokeh is not the point and never was. A 28mm at f/2.8 does not throw much out of focus, and what it does render is fine rather than creamy. Buy this lens for what is sharp, not for what is soft.

It earned a following among travel and street shooters who wanted a compact, autofocus alternative to a Leica M. The Contax G2 with the 28, 45, and 90 was a real working kit for reportage and travel through the late 1990s, light enough to carry all day. The 45 Planar and this 28 are the two most loved lenses in the lineup, the ones people reach for first.

The honest weakness is the body, not the glass. Contax G autofocus is slower and less sure than a manual rangefinder, and it can hunt in dim, low-contrast scenes in a way that frustrates anyone coming off a Leica. Worth knowing which body you have: the G1 was passive-only, while the G2 added active infrared triangulation specifically to help it lock in close, dark, and low-contrast situations. The lens itself has no real flaw beyond modest mechanical vignetting wide open. The other catch is mount lock-in. These only fit Contax G bodies natively, and adapting them to mirrorless is fiddly because of that same short back focus.

Today it trades for a fraction of the Leica 28mm Elmarit it gets cross-shopped against, and it holds its own optically. People still hunt them down precisely because nothing else gives this much corner sharpness and this little distortion for the money. For metering, it has no shutter of its own, so it leans entirely on the G body. Set Zone Light Meter to the body's full speed range and meter wide open in dim interiors before you stop down.