Hello Dmitry, Andrew!
Thank you, you just helped me to solve another problem linked to the one discussed here.
I struggled with grading Sony HLG footages to rec 709. I used the recommended and expected workflow with DaVinci YRGB Color Managed configuration, separate color space and gamma, with input and timeline set to Rec.2020+Rec2100 HLG and output set to Rec.709 20.4
The result was terrible. Rendered footages appeared with a HUGE color shift, lost contrast and oversaturated colors, harsh gradients, totally unusable. They aren't match not my GUI (not-calibrated) nor calibrated monitor connected via DeckLink.
After reading this thread I tried to play with the output and timeline setting.
Here is the results.
1. With Color Management set to DaVinci YRGB and timeline set to Rec.709, I managed to receive pretty good results, both using CSTnode, 3DLUTCreator for color space conversion, or just grading with regular DaVinci tools. The resulted footages look pretty close to calibrated monitor in QuickTime viewer (yes, with some slight differences but it is close enough for my needs). The results are pretty the same with Timeline set to Rec.709 scene and Rec.709 Gamma 2.4, though the Gamma 2.4 export looks closer to uncalibrated GUI viewer and "Scene" export was closer to the calibrated monitor - but the difference are not critical.
2. But which is more important, the "pure" workflow with Color Management set to DaVinci YRGB Color Managed, with HLG timeline and Rec.709 output, works just perfect when I set Output Color Space to Rec.709/Rec.709!
As I wrote above, I found no critical differences between Timeline set to Rec.709 scene or Rec.709 2.4 - at least for my needs (I works for stock videography, and I have no real clients, so I don't need to be extremely precise in my grading - it should look "nice" and more-less properly but not more). But the level of color and contrast distortion in clips produced from HLG footages with HLG input/timeline and Rec.7-9 2.4 output was totally unacceptable. Setting the Output Colore Space into Rec.709/Rec.709 solved this problem.
Some screenshots attached. The resulting footage in QuickTime in front of DaVinci GUI viewer with the open Color Management settings; filenames in the QuickTime windows' titles describe the process and the corresponded settings are on the screen. Please take a closed look to the 2020 HLG -> Rec709 2.4 results (the last screenshot).
![ice_screenshot_20200129-175058.jpg](./download/file.php?id=29040&sid=cb71b9db5c81706c11cdfd15b8f3fc08)
- ice_screenshot_20200129-175058.jpg (281.68 KiB) Viewed 26220 times
![ice_screenshot_20200129-172526.jpg](./download/file.php?id=29039&sid=cb71b9db5c81706c11cdfd15b8f3fc08)
- ice_screenshot_20200129-172526.jpg (283.06 KiB) Viewed 26220 times
![ice_screenshot_20200129-171905.jpg](./download/file.php?id=29038&sid=cb71b9db5c81706c11cdfd15b8f3fc08)
- ice_screenshot_20200129-171905.jpg (293.6 KiB) Viewed 26220 times