: H2A has a lot more contrast, probably as a result of pushing the HDR
: lighting; that means there are a lot of darker areas than the original
: (and things in a dark setting are more likely to be darker uniformly
: rather than the odd lighting in Halo 2.)

Which is odd though, the Sanctum of the Hierarch's on the level High Charity were brightly lit compared to the original game where you needed to use a flashlight.