You asked
Canon rf 7 14mm f 2 8 3 5l fisheye stm vs canon rf 10 20mm f 4l is stm?
The Canon RF 7-14mm f/2.8-3.5L Fisheye STM is the specialist. Its wide end gives a 190-degree circular image, and it's the one to pick if that look is the point. It's brighter at the wide end, but it has no stabilisation.
The Canon RF 10-20mm f/4L IS STM is the everyday wide zoom. It's steadier handheld thanks to its stabilisation, and it's the better fit for landscapes, where you'll usually be stopped down to f/8 or f/11 anyway. The landscape guide explains why f/4 zooms often make sense there.
Both fit the same Canon RF bodies, so the choice comes down to the look you want.
Written by Claude from this site's pages.