The current tone mapping controls (2013 for me) seem to not have very clear functionality.
Saturation seems to desaturate the rendered image, not just the HDR where by part of a model that should have bright hues per their shader color become gray.
It would be valuable to be able to desaturate just the HAD to create more "studio-like" neutral lighting from HDR images that have a strong color cast.
Likewise, the Gama control seems to affect the whole image, not just the HDR. Since HDR images are in a linear color space, it is valuable to be able to output an image in Gamma 2.2 (sRGB) space, but because the shader colors are not gamma corrected, only setting Gamma to a value of 1 produces reliable color results.
So either we need a gamma control for just the HDR that helps us tune the lighting (maybe more like a contrast setting?) or we shoulde be able to adjust the Gamma and the color values of the shader automatically counter correct in the background to produce expected color.
Exposure seem to work as I would expect however.
