TTArtisan M 90mm f/1.25

TTArtisan M 90mm f/1.25

When TTArtisan released this lens, it stood out as an unusually ambitious entry: a short telephoto with a maximum aperture faster than anything Leica itself had offered at this focal length. Reviewers noted that even Leica stopped at f/1.5 for its own 90mm, having reserved f/1.25 for the 75mm, so a 90mm f/1.25 sits close to the practical limit of what can be built for the M mount [1]. The appeal is straightforward: an extreme large-aperture portrait look at a small fraction of the cost of comparable Leica glass, which is why it drew attention from budget-minded shooters and curious Leica owners alike[2].

Optically the lens uses an 11-element, 7-group design with a ten-blade diaphragm, and it is a large, heavy instrument by M-mount standards. Its 72mm entrance pupil is part of why the barrel is so substantial; the lens weighs about a kilogram, and reviewers describe its size and weight as a meaningful trade-off. Build quality is solid, with engraved and paint-filled markings, a high but smooth focus ring throw of roughly 160 degrees from the 1 m minimum focus distance to infinity, and an aperture ring with soft half-stop clicks. The lens is rangefinder coupled, and TTArtisan added a small bottom tripod foot plus a user-adjustable rangefinder cam that can be calibrated at home with the supplied screwdriver, a feature the Phillip Reeve review praised highly. A 77mm front filter thread and a screw-in hood are part of the package. On a rangefinder body the bulk has handling consequences: at close range the lens can intrude into the viewfinder and even cast a shadow on the rangefinder patch, and accurate focus wide open near 1 m is difficult through the optical finder, so live view on a mirrorless body is often easier.

Beyond the M-mount version, TTArtisan has offered the same optical block in mirrorless mounts, broadening availability for users who adapt or shoot natively on other systems. No distinct factory special editions of the M-mount lens are widely documented.

Optical qualities

Rendering The lens is built around its aperture, and its defining trait is very strong subject isolation with smooth background blur at portrait distances. It is not a corner-to-corner optic and shows several compromises typical of an extreme fast design, but for its intended use as a portrait lens the central rendering is the point.

Sharpness Wide open the center is described as surprisingly contrasty for an f/1.25 lens, while the midframe is noticeably softer and the corners remain weak even stopped down; performance is strongest at portrait distances rather than at infinity or the closest focus.

Bokeh and transitions Near the minimum focus distance the background melts away, with cat's-eye shapes present but not heavily pronounced; at medium distances the central blur stays very smooth but deteriorates toward the corners with some doubling of edges.

Flare resistance Flare resistance is a weak point. Shooting toward the sun, especially at wider apertures, produces ghosts, rainbow crescents, internal reflections and veiling flare.

Distortion and vignetting Distortion is low but slightly wavy, with no correction profile available at the time of review. Vignetting measured about 2.3 EV wide open and is described as roughly average for a lens of these parameters, while optical vignetting is significant as expected from so fast a lens.

Aberrations Lateral chromatic aberration is low and easily corrected, while longitudinal CA is present wide open; the review also notes focus shift on stopping down, which can be a concern on a rangefinder body without live view. The ten inwardly curved blades produce a jagged, "ninja star" shape on out-of-focus highlights once stopped down.

Digital use The lens was tested on both Leica M digital bodies and adapted on full-frame mirrorless, with the thicker sensor cover glass of some mirrorless cameras noted as a factor in corner results.

History

Development and Launch TTArtisan introduced the 90mm f/1.25 in 2021 as part of its line of affordable manual rangefinder lenses, positioning it as a fast portrait option that undercut Leica's own fast 90mm and 75mm lenses by a wide margin. Reviews at launch framed it as following the company's earlier 50mm f/0.95 in offering unusual specifications at a fair price.

Production Evolution The same optical design was subsequently made available in additional mirrorless mounts beyond the original Leica M version, extending the lens to more camera systems.

Collector Notes Prospective buyers should weigh the lens's considerable size and weight, the difficulty of focusing it wide open through an optical rangefinder, and viewfinder intrusion at close range on M bodies. The user-adjustable rangefinder coupling allows owners to recalibrate the lens to their own camera, which is worth verifying on a used example. Note that some review figures for length and weight differ slightly from the values recorded here; this entry follows the confirmed specifications.