You asked
Is the canon rf 100 500mm f 4 5 7 1l is usm good for video?
I haven't tested this lens for video, and the site doesn't cover its video performance, so I can't say how the footage looks. The spec page does list image stabilisation and autofocus, which both help when filming. It's a long zoom, though, and it gets darker as you zoom in (f/4.5-7.1).
My video guide looks for a flip-out screen, a wide lens around 16-20mm full-frame equivalent, a microphone input and light weight. This lens doesn't fit the wide-angle or weight points, so I wouldn't choose it for vlogging or talking-head work.
It makes more sense for filming wildlife or sport from a distance. The wildlife and sport guide explains how reach works across sensor sizes. For a full-frame body to pair it with, the Canon EOS R6 Mark II is on the list of cameras this lens fits.
Written by Claude from this site's pages.