The recording of meeting #107 is now available.
Good morning @nick ,
you were of course right, I did not directly interpreted the AgX BT.1886 output as HLG.
I did the follwowing steps in Nuke before I wrote out the file. I am not 100% sure if this is the right way to do it. But in the comparison to the other images in the clip that I shared it looked right to me.
That makes sense, from the perspective of seeing a reasonable HDR image from the HLG, as you now have a Rec.2020 SDR image you are interpreting as HLG, and the log part of the HLG curve is similar to a highlight compression, so the HLG EOTF will expand that to the display. You’re basically doing “fake HDR” with inverse tone mapping.
Because it is an accidentally similar curve, rather than a deliberately matched one, it is possible that some values could get stretched out into the HDR range when they should not be. And I would be interested to know how much of a perceptual match you get between the SDR and HLG, as there is not anything in this approach which deliberately targets that.
I don’t know if this helps, this is a translations of troys latest Agx as a dctl:
this is my latest test (currently working on one that outputs rec2020 and p3d65 too)
And this is another dctl test by Troy that forms the image at wider gamuts.
The notes from meeting #107 are now also available.