Canon 5d3 1.1.3 Raw 12 bit 1920 x 649 x 1.67 50p footage Kitesurfing
Convert using MLV app then Davinci Resolve 18 using stretch to make 1080p.
Massive thx to Magic lantern for a usable raw video solution .
Crop Sensor expermental versions but just using MLV module only no audio no overlay ..
Icon showing yellow just able to record seamless with no lost frames .
https://youtu.be/JdvG6aYISmU
not fan of the 1080p and the YT compression, but the color contrast is totally amazing.
Have you tried crop modes for 3.5 K ?