Viltrox's ultra-wide f/1.4 prime for APS-C mirrorless — impressively fast for the focal length.
The Viltrox AF 13mm f/1.4 STM is an ultra-wide autofocus prime designed for APS-C mirrorless cameras, providing approximately a 20mm equivalent field of view. Released around 2022, it is remarkable for combining such a wide focal length with an f/1.4 aperture — a combination that barely exists from first-party manufacturers at any price.
Optical performance is impressive for the specification. Sharpness is good in the centre from f/1.4 and very good across the frame by f/2.8. The ED and aspherical elements control aberrations well. Coma is surprisingly well-managed for astrophotography use. Vignetting is noticeable wide open but correctable. The f/1.4 aperture enables astrophotography and low-light shooting at ultra-wide angles.
Available in Fujifilm X, Sony E, and Nikon Z DX mounts. Filter thread is 72mm. Weight is approximately 420 grams — substantial for an APS-C lens, reflecting the fast aperture. STM stepping motor autofocus is quiet and functional. Build quality is solid metal construction. Full electronic communication with the camera body including EXIF data.
Good availability on the used market at attractive prices. Check AF accuracy and smooth focus operation. An outstanding option for astrophotography on APS-C — the combination of 20mm equivalent, f/1.4, and autofocus is nearly unique. Also excellent for real estate interiors and environmental portraits where the ultra-wide perspective adds drama.