Viltrox AF 25mm F1.7 Air

The Viltrox AF 25mm F1.7 Air is a compact prime lens for APS-C mirrorless cameras. It comes in Fujifilm X, Nikon Z and Sony E mounts, so pick the version made for your system. On an APS-C sensor, 25mm gives a slightly wide view that suits street, travel and everyday shooting.

The f/1.7 maximum aperture is the main draw. That wide opening gathers light for evening streets and dim interiors. It can also soften backgrounds when you work close to your subject with space behind it. The trade-offs are a fixed focal length, no stabilisation and no weather sealing. Viltrox introduced the lens in 2025.

The Fujifilm X version weighs 6 oz (170 g) and measures 2.2 in (56 mm) long and 2.52 in (64 mm) across. Those measurements apply to the X version. Consider the camera and lens together when choosing a bag or carrying them on a walk. The front takes 52mm screw-in filters.

Framing is fixed at 25mm. On APS-C, the slightly wide view suits a street corner, a table setting or a group. Exact framing depends on where you stand. Move closer to make your subject more prominent, or step back to include more of the scene.

The f/1.7 maximum aperture is bright for a lens this size. In dim light it lets you keep the ISO lower than a smaller opening would force. The wide opening also softens backgrounds when you focus close, which suits portraits and single subjects in busy scenes.

Closest focus is 1 ft (30 cm), measured from the sensor. You can photograph nearby food, flowers and still-life subjects. The front of the lens sits closer to the subject than the sensor, so leave room ahead of the glass. Avoid shading a small subject when moving close.

Depth of field depends on aperture and focus distance as well as focal length. Stop down when people at different distances must stay sharp. Check focus on the most important subject and review the result before the group moves.

There is no built-in stabilization. For handheld shots in low light you need a shutter speed you can hold steady, or a camera body with its own stabilization. The f/1.7 opening helps by passing more light at the same ISO.

Weather sealing is absent too. The lens suits fair-weather and everyday indoor use, so keep it protected from rain and spray.

A 52mm polariser or ND filter attaches directly to the front thread. A polariser can reduce reflections from water and glass. An ND filter reduces the light reaching the sensor, which can help you retain a wide aperture in bright conditions.

The optical layout uses 12 elements in 10 groups, including two aspherical elements and one low-dispersion element. Aspherical surfaces help correct distortion and spherical aberration, useful when straight building edges and door frames fill a wide 25mm frame. The low-dispersion element helps reduce chromatic aberration, the colored fringes that can appear along high-contrast edges.