Leica Summicron-M 50mm f/2 (v5, current)

Put it next to the 50mm Summilux ASPH and you are really choosing between two jobs. The Summilux gives you f/1.4 and a softer, more romantic look wide open. The Summicron gives you f/2, less bulk, and roughly half the price on the used market, and it puts a sharp, high-contrast negative on the table from the moment you open the shutter. For most shooters who rarely actually use that extra stop, the Summicron is the saner buy.

This is the fifth generation of the Summicron-M, the one Leica built from 1994 and kept in the catalog through 2024. The optical formula is a classic double-Gauss, six elements in four groups, descended from the 1979 redesign and tuned rather than replaced. Wide open at f/2 it is sharp and high in contrast in the center, with the mid-frame and corners cleaning up as you stop down. By f/4 and f/5.6 it resolves more than film can record, which is the practical ceiling that actually matters with a rangefinder fifty.

The rendering is why people keep loading it. Bokeh is neutral and quiet, not swirly, not nervous, with backgrounds that go soft without drawing the eye. Out-of-focus highlights stay round near the center and pull into a gentle cat's-eye toward the edges wide open. Color is honest and runs slightly cool. Flare is well controlled thanks to modern multi-coating, though this is a long-running optical formula and not the latest-generation APO design, so heavy backlight will lift the shadows a touch. The focus falloff has that smooth Leica transition that sits a face forward off the background. Street and reportage first, portrait second.

The honest weakness is the close-focus floor. Like every M-mount 50, it stops at 0.7 meters because of the rangefinder coupling, so tight head-and-shoulders portraits and detail work are out. If you want to fill the frame with an eye, this is the wrong system. The f/2 maximum also means that in a dark bar you are working a stop behind the Summilux crowd, and on a meterless body you feel it.

Where it sits today: it has the reputation of the reference rangefinder fifty, and used copies hold their value well, though some of that is enthusiast lore stated as gospel. People cross-shop it against the Zeiss Planar 50/2 ZM, which is sharper wide open and a fraction of the cost, and against the APO-Summicron, which is optically better and several times the price. The v5 lives between them on rendering and size. One metering note. Wide open at f/2 in low light is exactly where a handheld reading earns its keep, so meter for the shadow you care about and let Zone Light Meter place it, rather than trusting an averaged reading that a bright window in the frame will pull two stops hot.