The idea of it being that light sheep doesn't make ANY sense in DayZ... You seem to forget the there are no lights on anywhere, no light pollution and no large sources of light other than the moon, and when it's anything less than a full moon (And even if there is...) it will be far, far darker than the picture you provided. I think making it quite a bit darker than that picture, but should still be faintly visible, I know I personally would never change gamma if I could at least see ANYTHING at night, but right now it's basically impossible and throwing flares every few hundred yards is just asking to be killed.