Voigtlander Ultron 28mm f/2 Aspherical (VM)

A fast 28 that fits in a jacket pocket and costs a third to a quarter of what a used Summicron-M 28 f/2 ASPH runs. That is the pitch, and it has held up for years. The Ultron 28mm f/2 is the wide-angle answer for people who want Leica framing on an M body without the Leica wide-angle invoice. Voigtlander brought out this aspherical M-mount version in 2021 to replace the earlier non-aspherical 28mm f/2 Ultron, and it has been the working photographer's fast 28 ever since.

Wide open it is already sharp in the center, with the corners catching up as you stop down past f/4. By f/5.6 the whole frame is crisp and the lens does what a 28 is supposed to do for street and documentary work: deep zone focus, plenty of depth, no fuss. The signature here is contrast. Voigtlander tuned this glass for punch, so shadows close down quickly and the image has real bite even on flat film. That suits Tri-X and HP5 beautifully. On color negative it can read a touch cool and contrasty, which some shooters love and others walk back in the scan.

The aspherical element is the whole point of the name. It is what lets a 28mm open to f/2 in a barrel this small while keeping coma and astigmatism in check at the edges, the things that turn night points of light into little comets. It mostly succeeds. There is some field curvature, so a perfectly flat brick wall will show the corners drifting if you focused dead center, but on real subjects at real distances you never see it. Bokeh at f/2 is fine rather than gorgeous; a 28 is not a portrait lens, and out-of-focus highlights can pick up a faint outline. Nobody buys a fast 28 for soft backgrounds.

Flare resistance on the modern coated ASPH is genuinely good. Point it near a streetlight or shoot into a low winter sun and it holds contrast better than you would expect from a wide this fast, though a hood is still worth using to clean up the last of any veiling haze. Voigtlander sells the LH-4N and LH-12 hoods as optional accessories rather than throwing one in the box, so budget for that. The only other thing to flag is generic: as with any used rangefinder lens, confirm focus accuracy wide open before you hand over money.

Where it sits today is where it has sat for a while. It is the sensible pick in the fast-28 conversation, cross-shopped against the Summicron-M 28 for those with the budget and the Zeiss Biogon 28 f/2.8 for those who can live a stop slower. People keep buying it because f/2 in a pocketable VM lens at this money is hard to beat, and because the rendering has its own look instead of being neutral to a fault.

One field note. At f/2 in dim interiors and on night streets you are metering at the edge of hand-holdable, so meter for the shadows you actually care about and let the contrast clip the highlights. The 46mm thread takes a small screw-in ND or a polarizer cleanly if you want to drag the shutter in daylight, and Zone Light Meter gives you the corrected speed once you dial in the filter factor.