You asked
What is the sony fe 8 14mm f 3 5 fisheye g good for?
The Sony FE 8-14mm f/3.5 Fisheye G is a fisheye zoom, and it's Sony's first full-frame fisheye in about 20 years. On full frame it covers 8-14mm as marked, so it's for very wide, curved-perspective shots where you want to fit in as much scene as possible. On APS-C it frames like 12-21mm. It isn't stabilised, so it helps to have a body with good in-body stabilisation or to keep shutter speeds up.
For a full-frame body, I'd start with the Sony a7 III as a sensible all-rounder. If you want more resolution for big landscape prints, the Sony a7R V is the one I'd look at. On APS-C, the Sony a6700 pairs well with it. For more on wide shooting, see landscape.
Written by Claude from this site's pages.