Post-Process Volume Color Grading 3D LUT Cube format incorrect color display

Hi all,

I've made some lookup tables for color grading, the png version display correctly, however the 3D LUT files in cube format for the external option under color-grading seems less saturated and has lower luminance values on color LUTs and grayscale.

I've tried different conversion scripts and proprietary software to convert my Haldclut images to cube format, they all give the same result.



Low definition LUT png 1024x32, higher contrast, brighter.



External Cube LUT file, Less contrast, lower brightness.

Could this be normal for the external LUT files, or maybe a color-space issue?
I've spent five days trying to figure this out, really stumped on this.

 

Just an update on the issue. I've tried conversion with Image 2 LUT, Premiere Pro, GREYC's Magic for image computing and IWLTBAP, DaVinci Resolve, exported files gives the same results across the conversion tools.

It seems other users have been experiencing this same issues over on the Github pages, https://github.com/Unity-Technologies/PostProcessing/issues/232