Sorry to bring back this old thread!
I’ve been trying to achieve the exact same thing (A log tone curve in a DCP, so that I can apply LUT’s designed for log footage via an enhanced profile) without much success! It seems Lumariver can import tone curves from a 3d LUT file, but am unsure and unwilling to spend the money if it’s not going to work as expected.
Just wondering if you have any more insight on all this since you last posted?
Hi Ryan! Yes, you can use Lumariver to make a profile with a log tone curve. Due to the way Lightroom processes color with profile tone curves it’s not 100% perfect, but you can get pretty close.
You’ll need a high resolution (8192 points or higher) 1D LUT (3D LUTs aren’t nearly precise enough) of the linear to log transform that also incorporates an exposure increase to bring the max raw file value (1.0) up to the max value for the log space (eg, I believe about 13.52 for Cineon, which is about 3.76 stops). Due to the way Lightroom profiles work you’ll also need to add an sRGB to Linear transform after the linear to log transform. So you would make your 1D LUT (using Lattice perhaps) by:
The tricky part then is to reformat that 1D LUT text file into the .json format accepted by Lumariver. I do it using excel and a text editor with find/replace to do the formatting. I can help you with that if you need it.
At some point in the pipeline, either in the Raw profile matrix, the Lightroom calibration panel, or by prepending a transform to your log 3D LUT in the enhanced profile, you’ll need to transform from your cameras native color to the log color space expected by your LUT. None of those options are perfect but you can get pretty close.
And finally, you’ll need to append a transform from the log 3D LUT to the color space that it’s being applied in (which you choose when making the enhanced profile).
Personally, I’d do the 3D LUT using Resolve so you can combine the transform from your cameras color + the log to REC709 LUT + the Rec709 to sRGB (or whatever space you use for the profile) with high precision. Then you can tweak whatever you want to shoot out variations later to use with the same base DCP profile.
It’s a lot, but it’s doable. Not perfectly doable, but doable… I’ll try to help if I can 