You asked
What is the ttartisan 14mm f 2 8 asph good for?
The TTArtisan 14mm f/2.8 ASPH is a manual-focus, ultra-wide prime for full-frame cameras. Its 14mm view is wide enough to fit a lot into a scene, which suits interiors, architecture and big landscapes. It's a fine pick if you enjoy slowing down and focusing by hand. Full-frame bodies it fits include the Nikon Z6 II and Canon EOS R6 Mark II.
On APS-C it frames like about 21mm (or 22mm on Canon), so it's still wide there. Remember that very wide lenses exaggerate whatever is closest to the camera, so it's a poor choice for flattering portraits; Portraits has better options. For how f/2.8 behaves on other sensor sizes, see the focal length converter.
Written by Claude from this site's pages.