https://www.opticallimits.com/sonyalphaff/1141-sony14f18gm
Not flawless but nice
Chief Editor - opticallimits.com
Doing all things Canon, MFT, Sony and Fuji
Well this Sigma is pretty iffy even on APS-H. :-) I would not have gotten it if I had stuck to APS-C cameras, of course, because what's the reason to get it when there are dedicated crop ultrawides that go wider, have filter threads, zoom and give better optical quality. :-)
Klaus, how would you compare Sony to Laowa 15mm F2?
Well, look at the charts. :-) The Sony lens is a magnitude better.
Chief Editor - opticallimits.com
Doing all things Canon, MFT, Sony and Fuji
Yeah, I guess Canon 10-22 / Nikon 12-24 introduced shortly thereafter solved the problem (for most people) in one fell swoop.