Just rendering in HDR doesn’t automatically make your monitor detect it as a HDR signal. The signal itself should carry metadata to indicate that it’s HDR, but I’m not sure how Aximmetry is handling that. Have you set your Decklink output to 10 bit? 

Thanks JohanF,  yes I have set my output to 10 bits and space color 2100 HLG that is HDR compatible. 

Can you set your monitor to HDR mode manually? 

Until next Monday I won't have access to the monitor. I'll check that. Thanks

Hi,

This is a complex topic, and without knowing your specific goals, it’s difficult to provide targeted advice. For example, HDR output requirements vary depending on whether you need HDR for post-production color grading or for live HDR output to an LED screen, as each scenario requires different setups.

The best bit breakdown things that can be set separately to HDR, so as to help clarify things:

1. Camera Input
Unfortunately, our documentation is somewhat lacking here, but you should generally follow these:

• Set the Input panel’s In Color Space parameter to match your camera’s output. Typically, this will be Rec.2100 PQ (Perceptual Quantizer) or Rec.2100 HLG (Hybrid Log-Gamma).
• Set the In Gamma Curve parameter to Color Space.
• For LED wall camera compounds, HDR is automatically enabled for Inputs when the HDR panel of the camera compound is turned on.
  Note that this is not supported for green screen camera compounds. If you need this, please let us know.
  For Video Input modules (Flow Editor), there are HDR Out pins. If disabled, the color range will have a maximum value of 1.
• In your Input Devices, make sure to set your input to 10-bit.

2. Rendering
For rendering, the settings you need to change are outlined in our documentation: https://aximmetry.com/learn/virtual-production-workflow/setting-up-inputs-outputs-for-virtual-production/video/hdr-input-and-output/    

3. Video Output
This is also detailed in the HDR documentation.
However, one detail is not clearly explained in the documentation:

• Any content generated inside Aximmetry and mixed with Unreal’s HDR content (for example, via the Overlays pin of the camera compound) will not be rendered or composited in HDR by default. To render this content in HDR, you must set the Pipeline Color Space to sRGB Linear in the Aximmetry Composer. More information is available here (see section: “HDR Rendering in Aximmetry”): https://aximmetry.com/learn/virtual-production-workflow/setting-up-inputs-outputs-for-virtual-production/video/hdr-input-and-output/#hdr-rendering-in-aximmetry 

Answers to your questions:

Q: My camera input is HDR 2020. In Aximmetry Video Input, should I select 8 bits or 10 bits?
A: You need to select 10 bits.

Q: For Output, I’m selecting 10 bits - 2100 HLG. What about “Keep” setting in input and output?
A: The Keep Color Space setting should not be enabled for HDR video (referred to as Keep in the Video Mode of a device). Turn it off.

Q: In Unreal project settings, should I change the Working color space from sRGB/Rec709 to Rec2020?
A: It doesn't matter. Unreal always calculates in HDR. The videos transmitted from Unreal to Aximmetry will automatically be converted to the right color space.

Q: Regarding PostProcess Volume, some Unreal specialists set Tone Curve Amount = 0 in Unreal Vanilla. Should I set this in the PostProcess Volume and AximmetryVirtualCamera Postprocess (required) component?
A: No, you shouldn't. It is fully independent of the HDR workflow.

Q: When I activate HDR in Aximmetry with default values, the colors are oversaturated. I don’t want to change HDR parameters because it will affect the original colors.
A: In an HDR workflow without tone mapping (such as for post-production), this is normal, you’ll want the unaltered color range so you can apply color grading later in a third-party linear editing program (for example, for every different shot or camera angle). For live production, or if you do want to adjust the look, you can use the Tone Mapping panel in Aximmetry.

About the HDR signal, embedding HDR metadata into SDI:
A: Aximmetry does not currently embed or detect HDR metadata in SDI signals. This information is rarely standardized or used reliably across the industry, so when working with HDR, you should not rely on embedded metadata for identifying HDR signals.

Warmest regards,