Laowa 12mm f/2.8 Zero-D (Canon RF)

Testers find the centre sharp from f/2.8 and the frame sharp almost to the edges once stopped down, with f/8 the best aperture and stopped-down corners rated good to very good. Distortion is slight, simple barrel rather than wavy, so straight lines stay straight for architecture. Chromatic aberration is low and lateral fringing is easy to remove.

Wide open, field curvature lowers corner contrast and coma or astigmatism shows in the corners, still visible at f/5.6, which matters for astrophotography. Vignetting is clear at f/2.8 (about 2.3 EV), and the aperture is not recorded in EXIF. Flare is hard to provoke but not class-leading, and the 7-blade aperture gives poorly defined sunstars.

The few owner reports read are mostly from DSLR and adapted-mirrorless users rather than native RF shooters. They value the lens for its width and straight lines, but several raise copy and setup issues: one owner reported back-focus on Nikon DSLR bodies and said the lens had been at the factory for months without being returned, and another found soft corners on a Sony body through a Nikon-to-E adapter that the reviewer suspected was too short.

Other readers worry about corner coma for star fields and about flare resistance.