You asked
Is the leica summilux sl 50mm f 1 4 asph good for video?
Here is what the site says about that.
From Leica Summilux-SL 50mm f/1.4 ASPH: Leica Summilux-SL 50mm f/1.4 ASPH: A prime lens by Leica for Full frame cameras, 50mm f/1.4. The 2026 redesign, smaller and lighter than the first Summilux-SL 50. Specs - Maker: Leica - Focal length: 50mm (prime) - Maximum aperture: f/1.4 - Made for: Full frame sensors - Mounts: L-Mount - Stabilised: no - Autofocus: yes What it frames like - On full frame (L-Mount): as marked, 50mm. - On APS-C (L-Mount): like 75mm on full ...
From Leica Summilux-SL 50mm f/1.4 ASPH (2016): Leica Summilux-SL 50mm f/1.4 ASPH (2016): A prime lens by Leica for Full frame cameras, 50mm f/1.4. The first version, over a kilogram; replaced by a much smaller design in 2026.
Quoted from this site's pages.