Leica Summicron-R 90mm f/2

Wide open at f/2 the in-focus plane is already crisp while everything behind it falls away into smooth, un-busy blur with no nervous edges. That pairing, real sharpness at the point of focus and quiet backgrounds, is the whole reason this lens has a following. It does not glow or smear the way some fast portrait teles do when you open them up. It resolves, then lets the background go.

It lived on Leica's R-series SLRs, the reflex system Leica ran in parallel with the M rangefinders, and the version this article is about (the non-APO Summicron-R 90) was made from 1970 to 2000. Leica later replaced it with a redesigned APO-Summicron-R 90mm ASPH that ran roughly 2002 to 2009, an apochromatic aspherical lens that is a different optic with cleaner contrast and far better flare control. If your barrel is the older one, that is the lens described here. On a 35mm body 90mm is the classic head-and-shoulders length, long enough to render features without distortion and to throw a distracting room out of focus, short enough to hand-hold and to use indoors.

Stop it to f/4 and the corners snap into line while contrast climbs. By f/5.6 to f/8 it is as sharp across the frame as you will ever need for landscape or repro work. Color is neutral, leaning very slightly cool, the kind of restrained palette that takes correction well rather than fighting you. The honest weakness is flare and veiling against the light. This is a 1970s optical design with the coating sophistication of its day, and shot into a window or a low sun without the hood, contrast falls off and you can pick up ghosts. It is a lens that wants its shade on and the sun behind you or well outside the frame.

Who reaches for it: portrait and documentary shooters who want a fast short tele with neutral, low-flare-into-the-light rendering, and people who already own R glass and want one lens that does double duty for faces and detail. It is not a cult bokeh object the way the 80mm Summilux-R f/1.4 is, or the way the soft-focus Thambar is (a screw-mount and later M-mount lens, never an R lens). It is the workhorse 90, and it is very good at being exactly that.

Today it trades as one of the cheaper ways into the R system, well under the price of the M-mount Summicron 90 and a fraction of the 80 Summilux. People cross-shop it against the Contax Zeiss Sonnar 90 f/2.8 and the Nikkor 105 f/2.5, and the Leica usually wins on rendering while costing more glass-for-glass. Many buyers now adapt it to mirrorless, where the f/2 speed and the 55mm filter thread (handy for a screw-in ND when you want to hold f/2 in daylight) keep it useful. One metering note for the dim interiors this lens is built for: at f/2 the depth is shallow, so meter off the brightest in-focus patch you care about rather than an averaged scene, since that is what the eye reads first. Set it as your key tone in Zone Light Meter, place it on the zone you want, and the wide-open exposures hold.