I have 2 GoPro Hero 5 that records in H.264 and 1 GoPro Hero 7 that records in H.265. When I import the H.265 footage from the Hero 7 it is darker than the fottage when opened by quicktime. No issues when import H.264 fottage from the other GoPros. Any ideas?
Check the footage interpretation. H.265 uses different color settings and can be encoded at 10bit and more, all of which affects colro rendering. You may also want to check the GoPro docs as I'm pretty sure soem of these things can already be controlled by adjusting the recording settings to your needs.