You asked
Is the viltrox af 14mm f 4 air good on aps c?
Yes, it works on APS-C, but it behaves differently there. The Viltrox AF 14mm f/4 Air is made for full frame, so on an APS-C body it frames like 21mm on full frame. That's still a useful wide, just not the ultra-wide it is on full frame. f/4 gives about the depth of field of f/6.
It fits the APS-C bodies in its catalogue, so choose by what you shoot:
If you want a lens designed for APS-C from the start, the Viltrox AF 35mm f/1.7 Air is a more natural everyday pick. Check the third-party lens notes to make sure your body supports it.
Written by Claude from this site's pages.