You asked
Canon rf 50mm f 1 8 stm vs ttartisan 50mm f 1 4 asph?
The Canon RF 50mm f/1.8 STM is the easier choice if you shoot a Canon RF body. It autofocuses, it's the cheapest fast lens on Canon mirrorless, and it's a great first prime. It isn't stabilised, though.
The TTArtisan 50mm f/1.4 ASPH gathers more light, and that matters for low light and shallow depth of field. It's manual focus only, so it suits people who don't mind focusing by hand. It also fits Sony E, Nikon Z, Canon RF, L-Mount and Leica M, which makes it useful if you change systems.
I'd pick the Canon RF 50mm f/1.8 STM for everyday shooting on a Canon. If you want the faster aperture or you use another mount, the TTArtisan is the one. For more on why a 50mm earns its place, see primes or zooms.
Written by Claude from this site's pages.