Laowa 20mm f/4 Zero-D Shift (L-Mount)

Testers found the centre very sharp from f/4 and the full-frame corners good wide open, with a soft zone in the inner mid-frame at f/4 that is gone by f/8. Shifted areas hold up well, and at f/8–f/11 they beat Canon's TS-E 17mm f/4L. Distortion is close to zero even when shifted, though not quite as low as on the 15mm Zero-D Shift, and longitudinal CA is very well controlled. Handling earns praise: the shift ring is easy to use, even with gloves, and the rotation clicks make multi-direction shifts simple.

The weak points are vignetting (about 2 EV centred and over 3 EV in a fully shifted corner wide open), lateral CA that is asymmetric when shifted and harder to correct, flare with the sun just outside the frame, and a hood that blocks sideways shift. Some markings are printed rather than engraved, the aperture clicks are faint and unevenly spaced, and there is no weather sealing. It is a DSLR-style design with a built-in adapter, so it is large for a 20mm f/4.

The one owner report read compares it with Nikon's PC-E 19mm, which he also uses: he rates the Laowa's optics as nearly as good as the Nikon and better than the PC-E 24mm, and prefers it with a polariser in urban work. He gets good results with up to about 9mm of shift with the hood fitted, using a slim filter.

His reservations are the small aperture ring, which makes the Nikon easier with gloves and in dim interiors, and that the hood limits filter choice. He also notes that spare parts are not supplied, so a lens needing parts has to be sent to China.