Apichai Sutthichat

Glad you find it helpful. from your initial post I’m assuming the LUT is Resolve’s Rec.709 Kodak2383 Since the LUT is giving out result in Rec.709 thus the image after the LUT is no longer in ADX10 anymore, so you would want to convert from Rec.709 result back to ACEScct. Not sure if you have anything done on the node of ACES transform, maybe accidentally? Other than that I can’t really make out what could be the reason.

On using LUT in an ACES workflow may be look up “LMT” on the ACES forum. In short LUTs aren’t made equal. Since the idea of ACES is to work in scene space and retain as much data till the end of chain then the output transform can happen after that. This allow you to not have to re-grade from scratch and be able the have the actual extra image data to go for a greater color volume of output if ever needed someday. So there are plenty of LUTs and plugins these days that are designed to work properly within this type of workflow. e.g. Lowepost’s Ravengrade Cinelook Pro, Pipeline LUTs from Cinegrain and many more. And I think there are some free to download options available, one from Cullen Kelly and maybe one floating somewhere on the ACES forum that’s derived from the XYZ space Print emulation.

It could be the white point conversion at some point from the CST (which you could turn off, but this case should leave as default) I believed in ACES(the actual working space), it is D60 (regardless of the white point of selected ODT which conversion will apply at the end). So when using the CST, since Rec.709 uses D65, there will be a white point conversion applied automatically back and forth which everything should turn out fine if CSTs on both end are set correctly. Then It could be a warmer white point from the Film Print LUT that you’re using (hence “D60” in the naming). Which I think is close to what the actual prints on the projection would give. For creative purpose you might want to go with the D65 version of the LUT if you want a cooler white. Using a LUT this way. It is important that you’re aware that the result is based on the empirical data that’s derived from the LUT which the color volume of the resulting image will be limited to what the output color that LUT gives out. (This case Rec.709) On the conversion, since the print LUT is expecting a film scan image, converting to “Rec.709/Cineon”should get you a better result. But I would just ditch the CST and use the ACES transform OFX instead, converting from ACEScct to ADX10 then apply the LUT then another ACES transform converting the Rec.709 result back into ACEScct. This should give a better match because it uses the appropriate math reversing the ACES RRT/ODT when converting back from Rec.709.

Been waitin, really appreciate this early release! Cheers.