Viltrox AF 40mm F2.5 Air Z

Testers found it sharp across most of the frame from f/2.5, with weaker but acceptable edges and corners and only slight barrel distortion. Lateral colour fringing toward the edges is easily corrected in software, and bokeh is smooth without onion rings despite the 7-blade aperture.

AF is fast, nearly silent and tracks well with face/eye detection. The build is basic plastic over a metal mount, with no aperture ring, AF/MF switch or sealing. Most reviewers call it outstanding value, and some rate it optically ahead of the cheaper first-party 40mm.

Owners use it as a light walkaround and street lens on Zf, Z5 and Z6-series bodies and are pleased with the image quality for the price. Several compare it favourably with the NIKKOR Z 40mm f/2, and the small petal hood is popular.

Some mention a plasticky feel, slower AF in low light, and that f/2.5 limits subject separation. A few report early quality-control or shipping issues.