You asked
What is the zeiss loxia 50mm f 2 good for?
The Zeiss Loxia 50mm f/2 is a manual-focus prime for full frame Sony E cameras. It has no autofocus and no stabilisation, so it suits people who like to focus by hand and take their time. On full frame it frames as a standard 50mm, a natural, slightly tight view that works well for portraits and everyday scenes. On APS-C bodies it behaves like a 75mm, which is a classic portrait length, and f/2 gives the depth of field of about f/3 there.
If you want it for people, the Portraits guide explains why a 50mm works so well for faces, and how it compares with an 85mm. For a broader idea of where a 50mm fits in a first kit, see Your first lenses. The lens fits a long list of Sony E bodies, from the Sony a7 to the Sony a6400, so check your body before you buy.
Written by Claude from this site's pages.