OBS HDR Settings: SDR White Level vs HDR Nominal Peak
This article explains the structural and functional differences between the “SDR White Level” and “HDR Nominal Peak Level” settings in OBS Studio. Understanding these settings is essential for content creators who want to stream or record in High Dynamic Range (HDR) while ensuring that standard overlays, capture sources, and high-intensity highlights render correctly without washing out or clipping.
In OBS Studio, HDR processing relies on the PQ (Perceptual Quantizer) transfer function, which maps specific digital values to absolute brightness levels measured in nits (cd/m²). When configuring HDR under the Advanced Video settings, “SDR White Level” and “HDR Nominal Peak Level” serve as the baseline and the ceiling of your video’s dynamic range, structurally defining how colors and brightness levels are mapped.
What is SDR White Level?
The SDR White Level (often referred to as “graphics white” or “paper white”) defines the target brightness for Standard Dynamic Range (SDR) elements when they are placed inside an HDR container.
In a typical stream or recording, you will mix SDR assets—such as your webcam, overlays, alerts, browser sources, and text—with HDR gameplay. Because SDR has no built-in brightness metadata, OBS must upscale these assets so they do not look dim or muddy alongside bright HDR gameplay.
- Structural Role: It acts as the baseline anchor point. It tells OBS, “Treat the absolute white point of any SDR source as this specific nit value.”
- Standard Values: The ITU-R BT.2408 recommendation suggests 203 nits for HDR reference white, which is the OBS default. Setting this too low (e.g., 80 nits) makes your overlays look dark and dull, while setting it too high (e.g., 300+ nits) makes text and webcams blindingly bright.
What is HDR Nominal Peak Level?
The HDR Nominal Peak Level defines the maximum brightness limit of the HDR video signal. It represents the absolute ceiling for specular highlights, such as explosions, sunlight, reflections, and lens flares.
When OBS encodes your stream or recording, it embeds static metadata (like MaxCLL/Maximum Content Light Level) to inform video players, streaming platforms (like YouTube), and HDR monitors how bright the video can get.
- Structural Role: It defines the upper boundary of the tone-mapping curve. If your game outputs highlights at 1000 nits, but your OBS HDR Nominal Peak Level is set to 400 nits, OBS will compress or clip the details in those bright areas.
- Standard Values: The default is typically 1000 nits, which matches the mastering standard for most consumer HDR displays and HDR10 content.
Key Structural Differences
The structural difference between the two settings lies in their mathematical function within the HDR color pipeline:
| Feature | SDR White Level | HDR Nominal Peak Level |
|---|---|---|
| Mathematical Role | Floor/Anchor: Scales and maps 8-bit/SDR colors upward into the 10-bit/BT.2020 space. | Ceiling/Envelope: Sets the maximum limit for 10-bit/PQ luminance values. |
| Primary Target | Non-HDR assets (overlays, webcams, alerts, capture cards in SDR mode). | Native HDR assets (HDR gameplay, HDR capture cards). |
| Visual Impact | Determines how bright and legible your user interface and text elements appear. | Determines the detail retention and intensity of bright highlights (prevents clipping). |
| Calibration Target | Standardized to human eye comfort for reading text on a screen (typically 203 nits). | Adjusted to match the master output capability of your game or monitor (typically 1000 nits). |
By correctly balancing these two values, you ensure that your SDR overlays blend seamlessly with high-fidelity HDR gameplay, preserving rich detail in both text-based graphics and intense, bright scenes.