You asked
Laowa 10mm f 2 zero d mft vs laowa 7 5mm f 2 mft?
These two are close siblings. Both are manual-focus Micro Four Thirds primes at f/2, with no stabilisation, and both fit the same long list of Micro Four Thirds bodies, from the OM System OM-1 to the Panasonic Lumix GH7.
The difference is how wide they go. On Micro Four Thirds, the Laowa 10mm f/2 Zero-D MFT frames like a 20mm on full frame, and the Laowa 7.5mm f/2 MFT frames like a 15mm. Both give about the depth of field of f/4 there.
I'd pick the 10mm for everyday wide shots, such as streets, interiors and travel, since it's less extreme and easier to compose with. The 7.5mm is for when you want a really wide view, like big landscapes or cramped rooms, and you don't mind the stretch at the edges.
Written by Claude from this site's pages.