Artra Lab Phi28 28mm f/2.8

The Artra Lab Phi28 28mm f/2.8 is an ultra-thin manual focus 28 mm lens for Leica M-mount. Artra Lab sells it as the ARTRALAB 28mm f/2.8 Φ28 and highlights a body only 13 mm thick. It is aimed at M-system users who want a very small everyday wide-angle. The lens is specified as full frame. Leica Rumors reported a teaser on 22 October 2025 and the official announcement on 16 December 2025, with glossy black paint and brass finishes following on 28 April 2026.

Optical design

The lens has 9 elements in 3 groups and a 10-blade diaphragm. The maximum aperture is f/2.8 and the smallest is f/16. The angle of view is listed as 75 degrees, which fits 28 mm on full frame. Artra Lab describes the lens as squeezing 9 glass elements into a body 1.3 cm thick and lists a low reflective multilayer coating. Leica Rumors gives a filter size of 28 mm, which the maker's specification table does not repeat, so that figure should be treated with caution.

Focusing and handling

Focusing is manual. The minimum focus distance is 0.3 m, which is shorter than the 0.7 m typical for coupled M lenses, so a rangefinder may not couple over the whole range. The specifications do not say how focus coupling is handled, so users should check this with the maker before buying for use with a rangefinder body.

Build and size

The lens is 13 mm long and 55 mm in diameter, and it weighs 200 g. The material is listed as brass. Finishes offered by Artra Lab include silver chrome, glossy black paint and brass. Because it is so flat, it is more of a pocketable lens than most M lenses.

Where it fits

The Leica Elmarit-M 28mm f/2.8 ASPH in this database has the same focal length and aperture. The Artra Lab lens is far flatter, but it is a manual design from a smaller maker and has little published data beyond the specification table. Artra Lab's Noxika 28mm f/2.8 is a related 28 mm pancake for Nikon Z.

Pros and cons

Pros

• Extremely thin at 13 mm
• 200 g with an all-brass body
• Close minimum focus distance of 0.3 m
• 10 aperture blades
• Three finishes offered

Cons

• Manual focus with no electronic communication
• Rangefinder coupling over the full range is not confirmed in the specifications
• Filter size is unclear between sources
• Smaller maker with limited long-term support information

Verdict

The Phi28 is an unusual lens that prioritises thinness above everything else. For Leica M users who want a discreet 28 mm that disappears on the camera, it is worth a look, but buyers should check the rangefinder coupling details first.