Redid HDRR. This is some screens of the same scene but with different settings applied.
The function being changed is defined as:
setHDRRParameters(bool bEnableVignette, float fExposure, int iFoggingColour, float fDeFog, float fGamma, float fBlurMix);
( click for bigs )

setHDRRParameters(true, 2, RGBA(0.5f, 0.5f, 0.5f, 1), 0.2f, float(1 / 2.2f), 0.25f);

setHDRRParameters(false, 3, RGBA(0.5f, 0.5f, 0.5f, 1), 0.3f, 0.62f, 0.25f);

setHDRRParameters(true, 3, RGBA(0.5f, 0.5f, 0.5f, 1), 0.3f, float(1 / 2.2f), 0.25f);

setHDRRParameters(false, 2, RGBA(0.5f, 0.5f, 0.5f, 1), 0.1f, float(1 / 2.2f), 0.25f);

setHDRRParameters(false, 2, RGBA(0.25f, 0.25f, 0.5f, 1), 0.1f, 0.62f, 0.25f);

setHDRRParameters(false, 2, RGBA(0.25f, 0.25f, 0.5f, 1), 0.1f, 0.62f, 0.75f);