Artralab 28mm f/2.8

ArtraLab 28mm f/2.8 Φ28

The ArtraLab 28mm f/2.8 Φ28 is a compact full-frame wide-angle lens for Leica M-mount cameras. Introduced in late 2025, it combines a 28mm focal length, an f/2.8 maximum aperture and an unusually small 28mm filter thread, the three specifications referenced by the Φ28 name.

The lens is built around an optical design of nine elements in three groups. Despite this relatively complex construction, the barrel extends only about 13 mm from the camera body, giving it a pancake-like profile suited to street photography, travel and everyday documentary use.

Design and Construction

The ArtraLab 28mm f/2.8 Φ28 uses an all-metal brass construction and is available in silver chrome, glossy black paint and exposed-brass finishes.

Its compact barrel measures approximately 55 mm in diameter and 13 mm in length. A small focusing lever is integrated into the barrel, while the 28mm front thread accepts the included screw-in hood and compatible filters.

ArtraLab officially lists the lens at 200 g. Independent measurements of at least one black-finished example have reported a considerably lower weight of approximately 129 g. Until measurements from multiple production versions are available, 200 g remains the official specification, while the discrepancy should be noted.

Optical Design

The lens contains nine elements arranged in three groups and uses a low-reflective multilayer coating. ArtraLab does not identify aspherical, extra-low-dispersion or high-refractive-index elements in its published specifications.

The aperture ranges from f/2.8 to f/16 and is formed by ten diaphragm blades. The stated angle of view is 75 degrees, which is consistent with a conventional 28mm full-frame wide-angle lens.

Its compact rear-focus geometry allows the optical assembly to remain close to the camera body. This contributes to the unusually thin construction but can also make digital-sensor performance more dependent on the camera’s sensor cover glass and microlens design.

Focusing and Handling

The lens focuses manually and is coupled to the Leica M rangefinder within the normal rangefinder-supported focusing range. Its minimum focusing distance is 0.3 m, extending considerably closer than the traditional 0.7 m mechanical limit of many Leica M cameras.

Focusing below the rangefinder-coupled limit requires Live View or an electronic viewfinder on compatible digital cameras. Film cameras and M bodies without Live View can still use the close-focus range through estimation or an external measuring method.

The extremely shallow barrel keeps viewfinder obstruction low and makes the lens well suited to compact M-camera combinations. The focusing lever provides a direct tactile reference for setting distance without substantially increasing the lens dimensions.

Image Characteristics

Independent testing describes acceptable corner sharpness at f/2.8, controlled chromatic and spherical aberrations, moderate contrast and relatively smooth out-of-focus rendering at short focusing distances.

The optical design may show some field curvature toward the outer image area, requiring slight focus adjustment when edge sharpness is more important than central sharpness.

Other field testing has identified a possible internal-reflection issue under certain lighting angles, producing a brownish central patch, reduced contrast and localized colour shift. The effect did not appear consistently in every orientation or scene, so further testing is required before treating it as a universal characteristic of the design.

These observations should be treated as practical reports rather than manufacturer specifications. Performance can also vary with camera sensor design, lighting direction and the use of the supplied hood.

Versions

The original release was offered in silver chrome. ArtraLab later expanded the range with glossy black paint and exposed-brass finishes.

The finishes share the same published optical formula, focusing distance and dimensions. They should therefore remain combined under one lens page, with finish stored as variant metadata rather than treated as a separate optical version.

Recommended variant metadata includes:

• finish
• measured_weight
• included_hood
• included_caps
• rangefinder_calibration
• coating_condition
• focus_condition
• aperture_condition
• box_included

Sources

• [1] ArtraLab. ARTRALAB 28mm f/2.8 Φ28, Full Frame M Mount. https://artralab.com/products/artralab-28mm-f-2-8-%CF%8628-full-frame-m-mount-brass
• [2] Manuell Fokus. Artralab 28mm f/2.8. https://www.manuellfokus.no/artralab-28mm-f-2-8/
• [3] Tobias Spranger. Photo London, 28mm Lens Comparison. https://tobiasspranger.substack.com/p/46-photo-london-2026-28mm-lll-9e