Blackmagic Forum

GregGreenhaw wrote:Does the HDR node try to account for ABL on the HDR tv. It appears to be behaving much different than normal curves. Then I increase the shadows the highlights drop.

Marc Wielage wrote:

GregGreenhaw wrote:Does the HDR node try to account for ABL on the HDR tv. It appears to be behaving much different than normal curves. Then I increase the shadows the highlights drop.

Every HDR TV set is different, so there's no way a single curve could compensate for all known models. The ABL mode also reacts dynamically, so it's unpredictable based on total screen content and average level.

My best advice would be to use a pro monitor like a Sony BVM-X300, which is going to have much more predictable behavior for HDR.

GregGreenhaw wrote:I was referring to the resolve scopes where slightly lifting the blacks in the curves on in HDR mode the highlights come down to compensate.

Rohit Gupta wrote:Is there any reason you are working in HDR mode when using shadow control? You should use the HDR mode on the node only when you need to grade something which is otherwise difficult to access using the controls, for example white clips, etc.

In the HDR mode, the curve in the mids will map to regular SDR highlights so you might be seeing that if you are not restricting your curve to only the blacks.

NOTE: DaVinci Resolve Studio includes a feature called “HDR Mode”, accessible through the context menu on individual nodes, that in theory is supposed to accomplish a similar thing. I’ve found it has really strange effects on Lift - Gamma - Gain that I can’t figure out how is supposed to help HDR grading: Gain races faster through the brights, Gamma is inverted and seems to compress the space, and so does Lift, but at different rates. If you’ve figured out how to make these controls useful, let me know…

GregGreenhaw wrote:I found HDR nodes behave better in RCM if I don't use separate gamma and gamut and I set the timeline colorspace to rec2020 and the output the hdr 2084 500nits. If this the correct way to do it or should I set both the timeline and the output to rec 2020 and hdr 2084 500nit. The author of the following blog also experienced weird behavior with the HDR node. http://www.mysterybox.us/blog/2016/10/2 ... vering-hdr

NOTE: DaVinci Resolve Studio includes a feature called “HDR Mode”, accessible through the context menu on individual nodes, that in theory is supposed to accomplish a similar thing. I’ve found it has really strange effects on Lift - Gamma - Gain that I can’t figure out how is supposed to help HDR grading: Gain races faster through the brights, Gamma is inverted and seems to compress the space, and so does Lift, but at different rates. If you’ve figured out how to make these controls useful, let me know…