You asked
Panasonic leica dg 9mm f 1 7 vs olympus m zuiko 8mm f 1 8 fisheye pro?
Both lenses are Micro Four Thirds primes with autofocus, and neither is stabilised. They fit the same bodies, including the OM System OM-1, so the choice comes down to the look you want.
The Panasonic Leica DG 9mm f/1.7 frames like 18mm on full frame, with depth of field close to f/3.4. It's the one I'd pick for everyday wide shots, interiors and travel.
The Olympus M.Zuiko 8mm f/1.8 Fisheye PRO frames like 16mm on full frame, with depth of field close to f/3.6. It's weather-sealed, and it's a fisheye, so it bends straight lines on purpose. Get it for creative, exaggerated pictures, not as your main lens.
If you're unsure how aperture translates across sensors, the focal length converter explains it.
Written by Claude from this site's pages.