Since my switch from Apple to Windows, I’ve had a less than stellar experience with my Wacom Cintiq 16. I couldn’t get brightness and contrast right and it has this odd behaviour.
Minimum brightness is at 75, goes up to 100, however when you move from 75 to 0 it seems to stay the same brightness before becoming dull at 0. It’s obscure and mystifying that Wacom would put out an application in this way. Yes, that strange behaviour is apparently apparently the settings working as designed?
This was confirmed when I tried to calibrate the screen with and the i1Profile software showed the screen was far too bright (off the charts on the profiler).
With the screen too bright, it contrast was also an issue as its hard to get good contrast if your screen is too bright, because even your blacks are to bright. This left the display with a much more waxy look at feel which made it hard to do editing. Contrast is important for fixing images or spot removal.
Through trial and error, I discovered that you can disable the Wacom brightness settings and use the Nvidia (from my graphics card) settings.
As you can see from this, I switched to the Nvidia settings which offered far greater control and I was able to adjust it to a point that matched the brightness requirements in the i1Display Pro calibrator.
So, if you’re having this issue, stop using the Wacom screen settings and use your graphics card settings. It should solve the problem.