Viltrox AF 135mm F1.8 LAB Z

Lab tests found centre resolution excellent wide open and the whole frame at its best around f/4–f/5.6, with negligible lateral CA, very low bokeh fringing and only about 1.4 EV of vignetting at f/1.8. Bokeh is smooth with a mild cat's-eye effect toward the corners, and several testers rate it close to first-party 135mm f/1.8 lenses optically.

Autofocus is quiet, accurate and fine for portraits, weddings and moderate action, but it is not as quick as the best first-party telephoto primes for sport. The size and weight, about 1.25–1.3kg, are the most common complaint.

Owners describe it as a Plena-class portrait lens at a third-party price and praise how clean the out-of-focus areas look at f/1.8. The build quality and the extra controls surprise people coming from older Viltrox lenses.

The complaints are weight and front-heaviness on smaller Z bodies, a lens display that some consider a gimmick, an aperture ring that needs two clicks per stop in click mode, and occasional firmware-related AF quirks that later updates fixed.