M1 MacBookPro 14_Lid being open allows external display to be brighter.
Working on sound for TV. Picture is dark and need to see action on screen to cut sync FX. Raised brightness as much as I could but details still lost in shadows. Thought maybe I could just look at this section on the M1 MBP screen and when I opened the lid the external monitor got brighter. Bright enough to see the details.
If I close the lid the external monitor returns to it's previous "lower" brightness level.
External monitor is the
LG UltraGear 34GK950F-B 34" 21:9 Curved 144 Hz FreeSync IPS Gaming Monitor
Connected via thunderbolt to Display Port 1.2
If I change the monitor to Display Port version 1.4 the brightness stays at the lower level no matter what I do.
I don't need an answer as to why this happens but I am curious if anyone happens to know.
MacBook Pro (2021)