You asked
Nikon z 40mm f 2 vs 7artisans af 40mm f 2 5?
Both are 40mm primes for full frame with autofocus, and neither is stabilised. The difference is mostly which camera you own and how much light you need.
If you shoot Nikon Z, I'd go with the Nikon Z 40mm f/2. It's small, cheap and good, and its f/2 opening lets in a little more light than the 7Artisans. It's a sensible everyday lens for a Nikon body.
The 7Artisans AF 40mm f/2.5 is the one to consider if you shoot Sony E or L-Mount, since Nikon's lens only fits Nikon Z. It also works on Nikon Z, so it's a useful option across mounts. Its f/2.5 opening is a half-stop slower, so it's less suited to dim rooms.
Written by Claude from this site's pages.