Viltrox AF 40mm f/2.5 STM Lens

The Viltrox AF 40mm f/2.5 is a compact APS-C prime lens built for mirrorless camera systems, available in Sony E, Fujifilm X, and Canon RF mounts. At just 170g, it's one of the lighter options in its class, making it a natural fit for photographers who want a capable fixed focal length without adding significant bulk to their kit. The 40mm focal length sits in standard territory, offering a perspective that works comfortably across a range of shooting scenarios.

With a maximum aperture of f/2.5, there's meaningful light-gathering ability for lower-light situations, and the aperture also enables some degree of subject separation. Autofocus is handled by an STM (stepping motor) system, which is noted for smooth and relatively quiet operation — a useful characteristic when shooting in quieter environments. The lens accepts 52mm filters, a compact thread size consistent with the lens's overall small footprint.

There is no image stabilization built into the lens, so shooters will need to rely on in-body stabilization if their camera supports it. Overall, it's a straightforward, lightweight APS-C prime for Sony E, Fujifilm X, and Canon RF mirrorless systems.