Yeah, you have to change these values:
Code:
float Luminance = 0.08f;
static const float fMiddleGray = 0.18f;
static const float fWhiteCutoff = 0.8f;
However... this will influence the entire scene. There's no really nice solution to this problem, unless you figure out a way to do the fog on top of the bloom somehow. I figure that would be possible through some sort of custom made fog code,
Cheers