You asked
Zeiss loxia 50mm f 2 vs ttartisan 50mm f 2?
Both are 50mm f/2 manual-focus primes for full frame, with no stabilisation, so the real difference is mounts. The Zeiss Loxia 50mm f/2 is listed only for Sony E. The TTArtisan 50mm f/2 covers Sony E, Fujifilm X, Nikon Z, Canon RF, L-Mount and Micro Four Thirds.
If you shoot a Sony E camera, both fit, and you're choosing between them on feel and build. If you use anything else, the TTArtisan is the only one of the two that works on your camera.
On Sony APS-C, both frame like 75mm, so either one gives you a classic portrait view. For a general reason to own a 50mm, see portraits.
Written by Claude from this site's pages.