Introduction
Mellow is a modern digital print stock designed with a gentle film curve to deliver soft and pleasing scene looks with a muted secondary color palette and subtractive color aesthetics.
Mellow comes with the incredible advantage of not being attached to any display transformation directly, thus allowing an incredibly easier HDR workflow compared to traditional LUTs.
It expects LogC as an input and returns LogC which allows a true "post - LUT grade" in a high color volume working space (LogC) if needed. Not to mention, it retains middle-grey fidelity and scores a green in all focused stress-tests.
Development
Mellow was crafted in DaVinci Resolve Fusion and derives most of its visual properties from negative film, color curves, tetrahedral color warping, film density, sat-curve and a sat-wrap in the YCH color model under a linear tone curve.
The tetra was used intricately to separate and compress certain hues and alter image density.
The entire color cube (divided into six tetrahedra) was remapped uniformly by warping the primary and secondary colors of the input signal (which correspond to the corners of the cube), without affecting the grayscale distribution of the image.
Stress Test Results
Mellow delivers as promised without being destructive. We don't see any veritable artifacts, chroma noise or out of gamut colors in the synthetic test charts.
Rec709 vs Mellow Print
The slideshow contains test images from Arri and RED.
The first image in every comparison shows the Rec709 version.
The second image shows the result with Mellow Print.
In all cases, a CST is applied after Mellow that transforms Arri LogC to Rec709.
No corrections have been made to the images upstream / downstream of the LUT.
Installation
Step 1
Go to Project Settings > Color Management > Lookup Tables
Click on "Open LUT Folder" and paste Mellow.
Step 2
Click on "Update Lists" and save.
Mellow should now be available in your LUT folder.
Step 3
Set 3D lookup table interpolation to "Tetrahedral" from Trilinear.
Implementation
Step 1
Color Space Transform – camera color space (in this case RWG/Log3G10) to ARRI/LogC
Step 2
Apply Mellow. (Mellow expects LogC as an input and returns LogC)
Step 3
Display Transform – Arri/LogC to Rec709/Gamma2.4
Special thanks : Cullen Kelly, Jason Bowdach, Nurali Kushkov, Rafael Bernabeu, Rodrigo Bodstein