The Importance of DRT Choice
Your DRT Choice is your first and most important choice when it comes to color grading. How you get to your display space or your monitor will dictate everything you do underneath it. This is from a four-part series looking at Contour by Cullen Kelly, a Look Dev OFX plugin that is DRT dependent. The looks you make will be different if you change your DRT. Check out the video below and also any of the links and screenshots to help do your own DRT Dignostics.
Prerequisites Downloads to Follow Along
Check out Contour and download a free trial here: https://procolor.ist/contour-official/
Watch @CullenKelly talk about it: https://youtu.be/Vf7sqod3uqI?si=xzfoI0waQa-kI2MC
P.s This is not a sponsored video. I paid for and own this OFX plugin and use it on every grade.
DRT's referenced in this video - Get them at Github
Diagnostic Tools
Building out the Testing Node Tree
N8 - RGB Chips DCTL
N12 - Your IDT
N1 - 7 - Normal Primary Adjustment Nodes (not neccesary for trialing DRT’s)
N14 - JP2499 DCTL
N16 - Open DRT DCTL
N17 - Davinci Resolve Stock CST
These all funnel into a layer mixer with a composite set to normal… So lowest active node is what goes thru.
What is happening
We are taking our Chips pattern that represents our Monitor’s LED’s at different levels of ‘wattage’. Combined all three colors and you should move along the path from Black/Shadow to Highlight/Pure White.
The Node tree puts the chips into a DW/I space using a CST transform from our footage which was Red Log.
The Chips now in DW/I go into our DRT platter and are converted to Rec.709 which is what we see on our scopes.
RGB Chips in Rec.709 Space
This is what our primaries look like with no modifications, just naturally being output in Rec.709 Space.
The outer edges are black and full saturation. And the inside point is where White exists.
Just by adding a DRT and moving it through a Color-managed workflow, we are introducing modifications and curves.
All of our work before the DRT/CST will be modified and conformed to their guardrails.
Neutering the DRT
What if we want our Reds to be Red, our Greens to be Green, or our Blues to be Blue, and we want/need to use a DRT to get from our working timeline space to our display space?
My preference in this situation is to use Open DRT with modified base settings. You can get a similar result by turning off everything in the stock CST but OpenDRT is still doing slightly better math I feel.
Big thing to Remember
Even choosing to use a neutered DRT/CST is a creative choice in the path to authoring an image. Just as choosing between JP2499 or anything else.