Thanks @jedsmith that’s extremely helpful!
Based on your post I’ve chained together the following nodes:
- gamut compress
- tonemap (Piecewise Hyperbolic Presets)
- Gamut convert (ACEScg to Rec709)
- Inverse EOTF (sRGB display)
alongside that I have your OpenDRT (v0.0.75) which, if I understand correctly does all of the above, plus chroma preserving.
here’s a screenshot of both (OpenDRT is the bottom image):
EDIT: I have updated the images to correct an error in my original settings for the OpenDRT.
Note how the “warm sunshine yellows” go to what I would describe as a “tangerine orange.” Is this is a necessary consequence of the chroma-preserving nature of the OpenDRT?
Here’s another comparison of the two, first of the Hyperbolic on the left and OpenDRT on the right:
While the Hyperbolic is not maintaining the colors (the 12 colors become 6), what it is doing is all going to white with increased exposure (compare the last row of both images). The OpenDRT is not going to white at 20 stops. In fact it looks the same at 100 stops as it does at 20. So it appears to never go to white. Perhaps that’s an artifact of this being a CG render, and the same would not happen in a photo? I’ll need to do further tests there…