Lumetri grade and exported .cube file does not match

[Richard Crook]

Maybe I'm missing something.  Does the Lumetri export option to CUBE leave out some information?

Here's the problem.  I created a grade that I use all the time with the Lumetri grading effect, and I want to export a .cube file that I can import into my camera for on-set monitoring.  The problem is, when I export the .cube...the grade doesn't match.

Here's the grade:

Here's the .cube file I created from that grade...imported as a creative LUT into Lumetri with no other settings adjusted:

Am I missing something here?

[chrisw44157881]

i right click nest, then apply lumetri to the nested sequence. then the lut matches my transform in adobe media encoder. also this matches if I add the lut in AME in its export tab. without one of these steps, my luma transform lut will fail. I can then continue in this fashion with lut difference generators such as this free one.

https://sellfy.com/p/aQ1y/

[Richard Crook]

Just to be clear, the problem isn't with exporting the video.  That works fine.  The issue is exporting a cube file.

BUT...I did try and nest the footage and apply the Lumetri with the look LUT and export a cube, and the problem remains. 

[axelmillar11]

Hi! Has this been solved? I'm having a very similar, if not the same, problem. I applied a .cube file to an adjustemnt layer, then I modified color curves, saturation, etc and exported this as a .look file. Now, if I use this .look file in the computer where I created it, it works, BUT If I use it in a different computer (same footage) it doesn't work at all. If I export it as a .cube file, it looks completely different. If I save it as a lumetri preset, it works everywhere.

[R Neil Haugen]

Axel....

Not all color/tonal corrections can be transferred to a LUT ... LUTs are said by colorists to be the dumbest math out there. All a LUT does is have a chart ... pixels with X/Y values become S/Q values ... and so on. That's it. So not everything can be reduced to a LUT. It's why there's so much trouble with LUTs clipping or crushing things. HSL secondary corrections at times will not properly be "applied" via LUT to another clip, for instance.

Which is why saving something as a Lumetri preset "works" when the other's haven't. Saving it as a preset means the entire effect will be set as you last used it. Saving as Cube and as Look are similar to each other but not exactly the same. Yea, at times they can get different results.

Neil