You asked
7artisans af 10mm f 2 8 vs viltrox af 9mm f 2 8 air?
Both are small, autofocus f/2.8 primes for APS-C, and both fit Sony E, Fujifilm X and Nikon Z. The main difference is the field of view. The Viltrox AF 9mm f/2.8 Air frames like 14mm on full frame, and the 7Artisans AF 10mm f/2.8 frames like 15mm. If you want the wider, more dramatic view for interiors, architecture or landscapes, I'd pick the Viltrox. If you want something a little less extreme for street and everyday use, the 7Artisans is the calmer choice. Neither is stabilised, so keep an eye on shutter speed in low light. For how crop factors change the numbers, see the sensor sizes guide.
Written by Claude from this site's pages.