Leica Noctilux-M 50mm f/0.95 ASPH

For years this was the fastest aspherical lens you could put on a 35mm camera, and Leica knew it. f/0.95 on a 50 is not a marketing number you ignore. It is only about a seventh of a stop faster than the old f/1.0 Noctilux it replaced in 2008, a difference you would never see on a meter, but the redrawn optics changed what the lens does wide open. Depth of field at f/0.95 on a portrait is measured in millimeters. Focus the near eye and the far eye is already going soft. The thin slab of focus is the reason to own it, and it is also the reason most people shouldn't.

Wide open it is not clinically sharp, and anyone who tells you otherwise has not shot it at f/0.95 in real light. The center has bite, but there is a veil of glow and a gentle field curvature that pulls the plane of focus into a slight bowl. Stop down to f/2 and it sharpens into something genuinely excellent across the frame; by f/4 it is excellent edge to edge and competitive with Leica's best 50s, though the APO-Summicron still out-resolves it. Most people do not buy it to shoot at f/4. They buy it for what happens at f/0.95: a subject sitting in that thin slab while everything behind it dissolves into smooth out-of-focus discs that stretch to cat's-eyes toward the corners. Backlight it and you get a creamy bloom around highlights instead of harsh contrast. Near the center, specular points come back as soft rounded blobs. Toward the edges, optical vignetting and the non-round blades turn them into cat's-eyes and, at distance, busier shapes that some shooters find distracting.

The design is a redrawn aspherical double-Gauss, floating elements included so close focus holds up. It is heavy and front-thick, with a 60mm filter thread that is unusual in the M line, so your regular 39mm or 46mm filters do not fit. If you want an ND to shoot wide open in daylight, and on color film at box speed you will need one, plan for that thread size. Flare resistance is decent for such a fast lens but not bulletproof; a bright source just outside the frame can lift contrast, so the hood earns its keep.

Who shoots it: available-light portrait and reportage photographers who want subject separation no other 50 can match, plus a fair number of people who own it because it is the most expensive 50mm Leica sells and they can. It is a four-figure-times-several lens, cross-shopped mostly against the 50mm Summilux f/1.4 ASPH, which is sharper wide open, lighter, cheaper, and the more sensible choice for almost everyone. The Noctilux is not the sensible pick. It does one look in one kind of light, and it does that better than anything.

The honest weakness, beyond price and weight, is that razor focus plane on a rangefinder. The M's patch is precise, but at f/0.95 your own focus error and even subject sway between focus and shutter release will miss the eye. Expect a real keeper rate, not a frame-for-frame one. One practical note for film shooters: in the dark bars and stages where this lens belongs, meter it wide open and let Zone Light Meter hold the f/0.95 reading while you pick the shutter speed, because half a stop of metering slop is the difference between a printable negative and mud when you are already at the bottom of the light.