Notice of Meeting - ACES Output Transforms Architecture VWG - Meeting #22 - 07/07/2021

Hello again,

I have uploaded twenty exr files in B&W using the latest version of the saturation node from Jed with the following options :

image

The exr files have the following characteristics :

  • Encoded as ACES - ACES2065-1 with proper metadata (ACES compliant EXR).
  • Full HD (1920*1080) with correct metadata (dataWindow and displayWindow being the same : 0,0,1919,1079 to avoid any CTL crash).
  • To avoid any ambiguity, there are two suffixes (‘lin_ap0’ for the colourspace and ‘BW’ for the version).

Some of these exr are more interested than others. But I thought it would be better to convert/upload all of them to be safe. It has been a very interesting “exercise”. A couple of examples jumped out to me immediately.

The loss of tonality using ACEScg primaries on the spheres is quite interesting :

I was pretty much pleased by the shaping here :

Same thing with my light sabers using ACEScg primaries :

This reminds me of the exposure sweeps I did back in February :

Same thing here :

It is just amazing how colour affects our visual perception :

And our little stick boy using ACEScg primaries :

With a nice shaping/tonality in its B&W version :

I used Jed’s Output Transform Nuke implementation. It is a perfect match to the CTL code and it is easier for me to generate frames. I hope that’s okay. I am wondering if we could use these “luminance” tests as a ground truth for tonality when we’ll switch back to their colour versions.

Hope it helps a bit,
Chris