Hi Prateeksrivastav10,
I think I saw the initial presentation of that video too.
ACES works differently than YRGB in resolve, but when you use a 3D-LUT, also not so much from a work step perspective.
You are used to work in DaVinci-YRGB and when you work with an ALEXA LogC Clip, I guess you would not apply the LogC2Rec709 3D-LUT in the Media page and the move over to the Color page.
I assume you prefer to add the 3D-LUT in a serial node in the Color tab.
Your screenshot above is taking your scene referred camera data (ACEScct) , apply a Rec.709 (display referred) view transform to it, which is a lossy conversion. Then you “want” to grade this result, promote it back to ACEScct and apply again whatever ODT (in your case also Rec.709).
This sounds similar to me like applying a 3D-LUT already in the media page. It is the wrong place, when you want to preserve all your high dynamic range data and wide gamut that the camera can record.
A lossy conversion should always happen at the end of the process chain and not in the middle.
If we actually saw the same presentation, then it was shown there that this workflow “works”, but the examples had a limited dynamic range, a 0-1 gradient and the 4 color grad had colors that were limited to the Rec.709 gamut.
The moment you try this workflow with a camera file from an ALEXA or any other high dynamic range footage, this proposed workflow breaks.
I also wrote about this topic before, you can find it here. Understanding Resolve Color Management with Nuke
I hope this helps.
Best
Daniel