You asked
What is the samyang af 24mm f 1 8 fe good for?
The Samyang AF 24mm f/1.8 FE is a compact, fast wide-angle prime, and its main job is night-sky photography. The f/1.8 aperture gathers plenty of light for stars and the Milky Way, and the lens is small enough to carry on a long walk.
On full frame you get a true 24mm view. On APS-C it frames like a 36mm lens, so it becomes a tighter view that suits everyday shots better than wide landscapes. It has autofocus but no stabilisation, so for star photography a tripod is a must.
It fits a long list of Sony E bodies. For full frame, the Sony a7 III is a sensible partner. If you want something lighter on APS-C, the Sony a6400 pairs well with it.
Written by Claude from this site's pages.