HDR Fundamentals
HDR captures significantly more detail in the brightest and darkest areas of an image, using higher bit depth to reduce color banding and enable smoother gradients.
Dynamic Range (Stops of Light)
Bit Depth & Color Representation
Color Gamut Coverage
Luminance Perception
Our eyes don't perceive brightness linearly. We're far more sensitive to changes in dark areas than in bright ones. HDR's PQ transfer function is based on this principle, allocating more data to shadow and mid-tone details.
Wide Color Gamut
HDR leverages Rec. 2020's wide color gamut to reproduce a larger portion of visible colors compared to SDR's Rec. 709, resulting in richer, more lifelike images with deeper saturation.
Transfer Functions
Transfer functions are mathematical models that map digital code values to light levels on a display. HDR uses PQ and HLG to manage its vast dynamic range.
PQ vs HLG Curves
Perceptual Quantizer (PQ)
An absolute, perceptually uniform transfer function designed for mastering. Maps code values to absolute luminance (up to 10,000 nits), ideal for cinematic content with precise creative control. Relies on metadata for display optimization.
Hybrid Log-Gamma (HLG)
A relative, display-referred function designed for broadcast. Its key advantage is backward compatibility - a single HLG signal works on both HDR and SDR screens without metadata. Practical for live production.
HDR Formats
The HDR landscape consists of various formats with unique technical specifications and ecosystem support. Understanding these is vital for production and distribution decisions.
| Format | Metadata | Bit Depth | Transfer Function | Licensing |
|---|---|---|---|---|
| HDR10 | Static (MaxCLL/MaxFALL) | 10-bit | PQ (ST 2084) | Royalty-free |
| HDR10+ | Dynamic (scene-by-scene) | 10-bit | PQ (ST 2084) | Royalty-free |
| Dolby Vision | Dynamic (frame-by-frame) | 12-bit capable | PQ (ST 2084) | Proprietary |
| HLG | None required | 10-bit | Hybrid Log-Gamma | Royalty-free |
HDR10
Baseline HDR format with wide compatibility. Static metadata means tone mapping is determined by the display based on single data points for the whole content.
Dolby Vision
Premium format with the most granular metadata and higher bit depth. Enables highly precise, creator-intended tone mapping on certified displays for optimal results.
HDR Display Technologies
Different display technologies offer unique strengths for HDR reproduction, from perfect blacks to extreme brightness.
| Technology | Peak Brightness | Contrast | Black Levels | Best For |
|---|---|---|---|---|
| OLED | 800-1500 nits | Infinite | Perfect blacks | Dark room viewing |
| QLED/Mini-LED | 1000-3000+ nits | High (local dimming) | Very good | Bright rooms |
| MicroLED | 2000+ nits | Infinite | Perfect blacks | Premium installations |
HDR Production Workflow
Engineering HDR video requires a comprehensive approach across the entire pipeline, from capture to delivery.
Acquisition
Capture with high dynamic range sensors (14+ stops), 10/12-bit depth, and log encoding to preserve maximum detail.
Post-Production
Grade in a calibrated HDR suite, working in nits. Manage color spaces and use HDR-specific tools for tone mapping.
Distribution
Deliver via streaming (HEVC/AV1), broadcast (ATSC 3.0), or UHD Blu-ray with metadata preserved.
Is HDR a "Scam"?
Addressing the common criticism of HDR technology.
While HDR technology offers objectively superior capabilities, it is sometimes labeled a "scam" by consumers. This perception doesn't stem from flaws in the technology itself, but from its frequent misuse and mishandling across the ecosystem.
The highly standardized and mature nature of SDR means most content and displays deliver a consistent, predictable experience. HDR, being more complex, introduces more points of failure. When HDR content is poorly mastered with incorrect metadata, or when displays marketed as "HDR compatible" lack the necessary peak brightness, contrast, or color gamut, the result can be worse than SDR - appearing too dark, washed out, or with unnatural colors.
TLDR: HDR is not a scam. It is a very powerful technology that is easy to misuse.