Laowa 25mm f/2.8 2.5-5X Ultra Macro (Canon RF)

Testers rate it very sharp for its magnification. At 2.5x it is very good wide open and peaks around f/4; at 5x diffraction already sets in at f/2.8 (an effective aperture near f/17), yet it stays very good to f/5.6, and above f/8 it softens noticeably, so f/11–f/16 are best avoided. It is sharper at 2.5x than at 5x. Chromatic aberration is practically absent at 2.5x and only faint at 5x wide open, and pincushion distortion is negligible.

The drawbacks are a dark band of mechanical vignetting along the edges at f/2.8–f/4, strong veiling flare with lights behind the subject, and handling details: the magnification ring is stiff, the aperture clicks are unevenly spaced, and the aperture index ring can turn on its own. One review loaner had dust inside. With no focusing ring and wafer-thin depth of field, it really needs a tripod or rail, and handheld video works best at higher frame rates.

Owners rate it highly for work beyond 1:1. One has used it almost daily for two years on Micro Four Thirds and full frame, handheld with off-camera flash rather than a tripod, and likes the depth the wide angle gives at high magnification. Another calls it very sharp and robust.

The complaints are the ones that come with ultra-macro work: it is hard to focus handheld, needs a lot of light, and often needs focus stacking, ideally with a tripod or beanbag. One owner wishes it also covered 2x.