Voigtlander APO-Lanthar 50mm f/2 Aspherical (VM)

Put this lens on a Leica M body, open it to f/2, and shoot a backlit branch against a bright sky. Look at the out-of-focus highlights. There is no green fringe behind the plane of focus, no magenta in front of it. That absence is the whole point. Cosina shipped this M-mount version in early 2021, about two years after the Sony E-mount original, and the apochromatic correction is not marketing. Longitudinal chromatic aberration, the color smear that plagues fast fifties wide open, is corrected to a degree almost nothing else in M-mount touches.

Sharpness is the second shock. Most f/2 lenses ask you to stop down to f/4 before the center bites. This one is already cutting at f/2, center to mid-frame, and by f/4 the corners catch up and the whole frame goes glassy. Contrast runs high. Blacks are dense, microcontrast on textures like fabric and tree bark is aggressive. If you have shot the old Lanthar lenses with their lanthanum glass and warm, gentle rendering, forget all of it. This is a different animal wearing the family name.

The bokeh is clean rather than characterful. Out-of-focus discs are smooth and neutral in tone, no swirl and no soap-bubble edges, though optical vignetting does squeeze them into cat-eyes toward the corners wide open, the way it does on almost every fast fifty. The tonal smoothness is deliberate, and it is also the honest weakness. People who want a fifty with a signature, the dreamy fall-off of a Sonnar or the nervous swirl of an old Biotar, will find this lens almost too corrected. It renders the truth and not much mood. For documentary, product, repro, and any portrait where you want the eyelashes to be unmistakably the sharpest thing in the frame, that is exactly right. For a romantic environmental portrait, you might reach for something flawed on purpose.

Where it sits in the market is the real story. Leica's APO-Summicron-M 50mm f/2 ASPH does the same job, arguably a hair better, for several times the money. The Voigtlander lands at a fraction of that and gives up very little. That is why it ended up in so many M shooters' bags as the sharp fifty, the one you grab when correctness matters more than character. It is heavier and longer than a classic Summicron, and the minimum aperture stops at f/16, but those are footnotes.

The 49mm filter thread is worth planning around. Rangefinder shooters who run a yellow or red contrast filter on black-and-white, or a graduated ND to hold a bright sky, lose real light at the negative. Dial the filter factor into Zone Light Meter before you shoot so the meter reads the exposure that actually reaches the film, not the scene in front of the glass. With a lens this corrected, you want the negative placed exactly, and the filter math is the easy part to get wrong.