Leica Summicron-R 50mm f/2 (v2)

Stop down a Summicron-R 50 to f/4 on a Leicaflex SL and you stop worrying about the lens for the rest of the day. It is the standard prime that came on a huge share of R bodies sold between the late 1970s and 2009, including as the supplied normal lens on the R3, the one that lived in the bag and got reached for first. The version 2 is the redesigned formula, a double-Gauss layout in the Planar tradition, and it is the one to find. The earlier version traded on character; this one trades on correctness.

Wide open at f/2 it is already sharp in the center with the gentlest falloff toward the corners, the kind of rendering where a portrait has bite in the eyes and the ears go soft on their own. Contrast is high without being brittle. The corners stay soft until you close down, and by f/4 the frame snaps to even sharpness edge to edge. Stopped down it resolves well enough that people who adapt it to high-resolution full-frame sensors report it holding up, where a lot of cheaper fifties from the same years fall apart. The out-of-focus rendering is smooth and a little clinical, not the busy backgrounds that some vintage fifties produce. Color is neutral and runs slightly cool. Flare control is decent for a lens of its era, but put a bright source in or near the frame and you can lose contrast, and reviewers who shot it hard into the light split on how much.

The honest catch is that this lens has very little of what people mean when they say a lens has soul. It does not glow, it does not paint, it does not do anything you can point to in a frame and call a signature. Next to a Summilux at f/1.4 or an old Summarit it looks almost charmless. If you want a fifty that visibly wrestles with its own aberrations, this is the wrong one; buy something older and slower-corrected.

The thing that keeps it interesting now is the price. Adapted to mirrorless it costs a fraction of an M-mount Summicron and out-resolves most of its price class. The usual cross-shop is the Contax Zeiss Planar 50mm f/1.7 or a late Nikkor, and the Leica answers on build quality and on how consistent it stays across the frame once stopped down. The Zeiss usually costs less, and to my eye it skews a touch warmer. R glass needs a working adapter and there is no electronic coupling, so you meter and focus by hand, which suits the lens fine.

There is no shutter in the lens; the R bodies are focal-plane, so flash sync follows the body. The 55mm filter thread is the practical number to know, common enough that screw-in NDs and grads are easy to find for shooting wide open in daylight. If you push this lens into close-focus work on a bellows or an extension tube, meter at the working distance and let Zone Light Meter fold in the bellows factor, since the extra extension costs you real light that an incident reading at the subject will not show.