You asked
Laowa 10mm f 2 zero d mft vs olympus 9mm f 8 fisheye body cap lens?
Both lenses fit the same Micro Four Thirds bodies, so the choice comes down to the look you want.
Pick the Laowa 10mm f/2 Zero-D MFT if you shoot in dim light or want some background separation. It's a proper f/2 prime that frames like 20mm on full frame, and at f/2 its depth of field is about that of f/4 there.
Pick the Olympus 9mm f/8 Fisheye Body Cap Lens if you want something tiny that lives in your bag and keeps almost everything sharp. Its fixed f/8 aperture means you'll need plenty of light, and as a fisheye it bends straight lines into a curved, dramatic look.
Both are manual focus and neither is stabilised. For most people the Laowa is the more useful lens. The Olympus is the fun one.
Written by Claude from this site's pages.