Carl Zeiss Sonnar T* 85mm f/2.8 (C/Y)

Every Contax shooter lusts after the Planar 85mm f/1.4. It is the portrait lens, the one on every wishlist and the one that pulls silly prices at auction. The Sonnar 85mm f/2.8 is the one a lot of them should buy instead. Two stops slower, less than half the weight, and by f/2.8 the gap in rendering between the two is small enough that most people would struggle to call it in a print. You pay for the faster glass mostly to buy the two stops, not the image quality at working apertures.

What you get is the Sonnar signature. The center is sharp from wide open, helped by the fact that f/2.8 is the maximum aperture and the design was never asked to do the impossible at f/1.4. Micro-contrast runs high. Color has the slightly cool, saturated look people mean when they say Zeiss. Backgrounds fall away smooth and quiet rather than busy, though this is not the glowing, dreamy separation of the faster Planar; the Sonnar reads a little more clinical, edges staying defined right up to the focus plane. The T* coating holds flare and veiling down when you shoot into a window or a low sun.

The Sonnar name traces to Ludwig Bertele's designs for Zeiss in the early 1930s, prized then for being fast and contrasty with few air-to-glass surfaces. Zeiss kept the badge for compact teles in the SLR years, this 85 and the Sonnar 100mm f/3.5 among them. Made for the C/Y bayonet that launched with the Contax RTS in 1975, the 85/2.8 came out of both West German and Japanese production over its life, in earlier AE and later MM versions, the MM glass playing nicely with the program modes on the later Contax bodies. It is tiny for an 85, which is most of the appeal.

Portrait shooters who do not need to work in the dark love it, as do people who want a short tele they can carry all day and forget about. On the used market it is one of the real bargains in the Contax Zeiss lineup, precisely because everyone else is busy fighting over the f/1.4. Adapt it to a mirrorless body and you get that Zeiss rendering for a fraction of what a native equivalent costs. The lens it truly competes with is its own sibling, and the honest answer is that most people never need the extra two stops.

The weakness is exactly what the spec tells you. It is an f/2.8 lens, so for available-dark work or the shallowest possible depth on a tight headshot, the Planar still wins. Like most Sonnars it carries a little field curvature, which you notice in flat copy work and basically never in a face. The 55mm filter thread is the small, common, cheap kind, so an ND or a polarizer is easy to find and screw on; feed the filter factor into Zone Light Meter and your shadow readings stay honest through the glass.