Viltrox has announced the AF 28mm f/4.5 Chip for L-Mount, the latest addition to a lens line that first appeared on Sony E-mount in October 2024 and subsequently extended to Nikon Z and Fujifilm X.

The defining characteristics of the lens are its dimensions and weight: at 13.2 millimeters long and 60 grams, it is one of the smallest autofocus full-frame lenses currently on the market, the compact form achieved through a series of deliberate design constraints. The aperture is fixed at f/4.5 and cannot be adjusted, which eliminates the aperture mechanism entirely. Manual focus is also unavailable; the VCM autofocus motor operates the lens, but there is no focus ring and no provision for manual override, which is an unusual limitation that removes a basic control from the photographer’s hands. There is no front filter thread either, a consequence of the lens’s minimal diameter. An integrated slide lever controls a built-in lens cap, removing the need for a separate cap to be attached or removed.

Optically, the lens comprises six elements in six groups, incorporating two ED elements and two aspherical elements. In place of a conventional circular aperture, Viltrox has used a polygonal diaphragm, which produces geometrically shaped starburst effects around point light sources rather than the rounded ones associated with multi-blade circular apertures. Minimum focusing distance is 0.32 meters.

Here are some sample pictures, courtesy of Viltrox: