Carl Zeiss Sonnar T* 90mm f/2.8 G

Hand someone a Contax G2 with the 90mm screwed on and the first thing they notice is how little there is to it. A 46mm filter ring, a barrel that barely clears the rangefinder housing, and a lens that weighs nothing in the bag next to anything you would mount on an SLR for the same reach. Then they shoot a roll, get the scans back, and go quiet. It is one of the sharpest lenses Zeiss made for the G system, and it was sized like an afterthought.

The design is a Sonnar, which on a short tele is exactly where that formula wants to be. Zeiss has been refining the Sonnar layout since the 1930s, and the original use case was a fast, compact lens with the contrast cranked up. The G version keeps that DNA. Wide open at f/2.8 it is already biting sharp across most of the frame, and by f/4 the corners snap into line with the center. Contrast runs high in the classic Zeiss way. Blacks land hard and the fine detail comes through crisp without any of the haloed edge you get from oversharpening. The T* coating handles flare cleanly, so you can shoot toward a window or a streetlight without the image washing to gray.

Out-of-focus rendering is smooth but not soft, which is the thing people argue about. The Sonnar gives you a quiet, slightly nervous background rather than the buttery wash of a Planar. Skin holds texture and the eyes are knife-edge crisp, which is why portrait shooters who found their way onto the G system rarely left it. Resolution stays ahead of what most films can record, so a flat scanner or a coarse emulsion will give out before the lens does.

The honest weakness is the autofocus, and it is a system problem, not an optical one. The G2's rangefinder-coupled AF struggles to nail the 90mm wide open at close range, where depth of field is paper-thin. Miss by a hair and the sharpest lens you own delivers a soft eyelash instead of a soft cheek. Shooters learn to stop down a touch, or to confirm focus and recompose carefully. On the early silver-label G1 the 21mm and 35mm were the lenses left out at launch. The 90mm was supported from day one, though some of those early bodies were fussier about locking onto it. So this lens asks for a careful operator, and it will let you know when you have not been one.

Today the G 90mm is the cheap seat of the trio. The 45mm Planar gets the love and the 21mm Biogon gets the collectors, so the 90 often goes for a fraction of what it should given what it does. People cross-shop it against the Leica 90mm Elmarit and walk away having spent a third as much for resolution that holds its own against it, with a touch more purple fringing wide open as the trade. The catch is the dead Contax G mount, no aperture ring control on adapted bodies, and a focal-plane shutter that lives in the camera, not the lens.

One metering note. At f/2.8 indoors the finder stays bright, so meter the actual highlight you care about rather than trusting an average. Set the working aperture in Zone Light Meter and place the skin tone where you want it on the scale, because with this lens the difference between a luminous portrait and a blown cheek is half a stop, and the falloff is fast enough to see.