You asked
Sigma 24mm f 3 5 dg contemporary vs ttartisan af 24mm f 3 8 mini?
Both are 24mm autofocus primes for full frame, so the choice comes down to mount, weight and brightness.
The Sigma 24mm f/3.5 DG Contemporary is the one I'd pick if you shoot Sony E or L-Mount. It's a little faster at f/3.5, and it's still pocketable.
The TTArtisan AF 24mm f/3.8 Mini is the lighter option, at about 57 grams, and it's the one for Nikon Z bodies. It's the slower of the two, but for a small, cheap-to-carry walk-around lens, that trade-off is fine.
If you're on Sony and want the brighter lens, go Sigma. If you're on Nikon Z, TTArtisan is your choice.
Written by Claude from this site's pages.