Cool image! You just got me interested in spectral analysis of stars 
Interestingly that pixel with the largest negative value (rgb=8.76902, -19.4676, 106.88 at x=2554, y=2051) is not the pixel with the largest distance. The distance for that pixel is rgb=0.9719, 1.1821, 0.0000. And the maximum RGB distances for this image is rgb=1.313, 1.234, 1.183 with no shadow rolloff, and rgb=1.032, 1.18, 1.067 with a shadow rolloff of 0.1.
I think this image might be somewhat in the realm of “synthetic” since it is an HDRI stitch as well. I would be curious to see how the source camera raw files compare.
I spent a bit of time gathering some distance data for a representative selection of the source imagery we have so far. These distance values are calculated with a shadow rolloff value of 0.1 to reduce meaningless distance values. And if a max distance is less than 1 the value is set to 1.
I was going to try to upload this as a quicktime but the format is not allowed so I will dump this as a big vomit of images. Hope that’s okay.
