The game DOES USE/APPLY Xbox and PS5 HDR Calibration settings but not PC ones.
The game has a good HDR implementation as it correctly leverages Xbox HDR Calibration while it offers an in-game Peak HDR Luminance slider (in nits) on PC which can go up to 10.000 nits along with other HDR controls while also providing good black levels.
The only problem on PC is that the value you put in-game for Peak HDR Luminance doesn't correspond exactly to the actual in-game Peak HDR Luminance (you need to aim higher to match what you want during actual gameplay) but we'll see that in a moment :)
For PC only:
If you have an LG OLED and:
> you're using Dynamic Tone Mapping or Dynamic Contrast:
Set Peak White slider to: 4000 (nits)
> you're using HGIG:
Set Peak White slider to: 1.000 (for 800 nits) or 1.200 (for G2/C4) or 2.000 (for G3/G4)
If you don't have an LG OLED and:
> you don't have an HGIG option:
Set Peak White slider to: 1.200 (for around 1.000 nits)
> you're using HGIG:
Set Peak White slider to the corresponding real Peak HDR Luminance of your TV in "nits" considering the following in-game values:
- 1.000 = 800 nits
- 1.200 = 1.000 nits
- 1.700 = 1.300 nits
- 2.000 = 1.500 nits
- 2.500 = 1.800 nits
- 2.800 = 2.000 nits
- 4.000 = 2.500 nits
For PC and Xbox:
Set the regular Brightness slider to 28 to fix an otherwise slightly too contrasted image and improve specular highlights without raising black levels.
Set UI Brightness slider to 200 for a balanced value.
BONUS:
Disable Chromatic Aberration & Disable Film Grain: by setting it to 0, to improve picture clarity
On PC: Set Motion Blur to Medium: as default High is a bit too much (especially with Frame Generation)
On PC: the game is VERY heavy when using Full Ray Tracing (or Path Tracing) so if you want to use that make sure to not exceed your VRAM limit (e.g. decrease DLSS preset to Performance and decrease Textures quality until your VRAM has some free room again)
On PC: DLSS Frame Generation is currently broken (it will stutter intermittently). Hopefully this will be fixed with later patches -> FIXED WITH PATCH 1.02 (but if you still have issues with frame pacing: Disable Low Latency Mode: Ultra from classic NVCP (only for this game)
Enjoy :)
-P