Apple's support document https://support.apple.com/en-us/HT208909 says:
"True Tone can also adjust these external displays when they're connected to your MacBook Pro with its lid open:
Apple Thunderbolt Display, using the Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 adapter
LG UltraFine 5K Display
LG UltraFine 4K Display"
However, I just received the 2018 MBP 15" today, and True Tone seems to work on my old LG 31MU97 (a 4K monitor which pre-dates the LG Ultrafine 4K and 5K monitors).
It seems that whatever True Tone color temperature that Apple decides to use on the laptop display is also used on the external monitor.
I'm guessing that True Tone will therefore also work on any other brand of external monitor, although I don't currently have any other monitors to test that theory with.
However, the MBP has no ability to alter the brightness/contrast settings on my external Monitor, since my monitor is not the official Apple Thunderbolt display or one of the special Apple/LG collaboration UltraFine models. I think there is a special thunderbolt-only communication channel which is why only those monitors support brightness adjustment (vs the official DDC/CI signalling standard that Apple don't seem to have implemented support for).
So I'm wondering whether I'm seeing the full True Tone benefits that someone with an UltraFine monitor would see? Or perhaps I'm only getting the color temperature adjustments, but if I had an UltraFine there would be brightness contrast auto-adjustments too?
"True Tone can also adjust these external displays when they're connected to your MacBook Pro with its lid open:
Apple Thunderbolt Display, using the Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 adapter
LG UltraFine 5K Display
LG UltraFine 4K Display"
However, I just received the 2018 MBP 15" today, and True Tone seems to work on my old LG 31MU97 (a 4K monitor which pre-dates the LG Ultrafine 4K and 5K monitors).
It seems that whatever True Tone color temperature that Apple decides to use on the laptop display is also used on the external monitor.
I'm guessing that True Tone will therefore also work on any other brand of external monitor, although I don't currently have any other monitors to test that theory with.
However, the MBP has no ability to alter the brightness/contrast settings on my external Monitor, since my monitor is not the official Apple Thunderbolt display or one of the special Apple/LG collaboration UltraFine models. I think there is a special thunderbolt-only communication channel which is why only those monitors support brightness adjustment (vs the official DDC/CI signalling standard that Apple don't seem to have implemented support for).
So I'm wondering whether I'm seeing the full True Tone benefits that someone with an UltraFine monitor would see? Or perhaps I'm only getting the color temperature adjustments, but if I had an UltraFine there would be brightness contrast auto-adjustments too?