You asked
Voigtl nder apo skopar 90mm f 2 8 vs ttartisan 90mm f 1 25?
Both are manual-focus 90mm primes for full frame, so the choice mostly comes down to light and mount.
The TTArtisan 90mm f/1.25 is the faster lens, and it's the one to pick if you want the shallowest backgrounds or shoot in dim light. It's listed for Sony E, Nikon Z, Canon RF, L-Mount and Leica M, so it suits more bodies. On APS-C Sony, Nikon or L-Mount cameras, it frames like 135mm.
The Voigtländer APO-Skopar 90mm f/2.8 is listed only for Leica M bodies. If you shoot a Leica M, it's the one that fits. Otherwise, the TTArtisan is the easier choice.
Written by Claude from this site's pages.