Laowa 15mm f/2 Zero-D (Canon RF)

Testers find the centre sharp, even outstanding, from f/2, but the outer field is soft at f/2 and barely better at f/2.8. Quality is fine from f/4, and the best results come around f/5.6 to f/8, with good to very good borders and good corners. Distortion is a highlight: slight barrel only, low enough for professional architecture. Lateral fringing is low and rarely distracting.

Vignetting is very high wide open (over 3 EV) and remains visible at f/8, and it cannot be corrected in camera. Flare is handled quite well for an ultra-wide, helped by a front element that is not bulbous. Build quality is very high and the de-click switch makes it attractive for video; the main practical drawbacks are manual focus, no contacts and no weather sealing.

A long-term user who took it on aurora shoots values it for being much smaller than fast 14mm alternatives while still focusing manually with ease at night. The all-metal barrel feels dense, the focus ring is well damped, and corner performance compares well with cheaper fast wides.

The complaints are vignetting that stays noticeable for a couple of stops, slight coma ('angel wings') on stars in the corners, and a metal hood that does not lock firmly, so a small bump can rotate it into the frame corners. Larger, more expensive fast ultra-wides are a little better optically.