I've been told that prog overrides the automatic brightness compensation, though the default behavior is the opposite of what you want, it gets brighter when the environment is bright and darker when its dark (external lightsources doesn't help much with making the screen content brighter, i imagine they made the automatic adjustment work like that because your eyes get used to the brightness of the environment and the screen itself would appear darker without the adjustment)


I myself just keep it set to fullbright (which also overrides the automatic adjustment) because with the automatic adjustments it it looks too dark for me even in a brightly lit room.