Computer Atlas

HDR

Also known as: High Dynamic Range, HDR10, Dolby Vision, HDR display, tone mapping

supplemental intermediate concept 5 min read · Updated 2026-06-08

High Dynamic Range imaging captures and displays a wider range of luminance — from very dark to very bright — than standard displays, requiring new formats, tone mapping, and colour science to render correctly.

Primary domain
Graphics & Media
Sub-category
Photograph Manipulation & Image Compression

In simple terms

A candle flame and a snow-covered landscape on a sunny day differ in brightness by about a factor of one million. A standard (SDR) display can only show a factor of about 1,000. High Dynamic Range (HDR) displays show up to a factor of one million — a much closer approximation of what eyes see in reality. A candle in a dark room actually looks like a point of fire rather than a washed-out blob. HDR requires new display hardware (local dimming LCD or OLED), new content formats (HDR10, Dolby Vision), and new software to correctly map the wide range of brightness values to what each display can show.

More detail

Key concepts:

Dynamic range: the ratio of the brightest to the darkest luminance a display can simultaneously show. Measured in nits (candelas per square metre, cd/m²).

  • SDR (Standard Dynamic Range): typically 100–300 nits peak, ~0.01 nit black → ~1000:1 contrast ratio.
  • HDR (High Dynamic Range): 600–10,000+ nits peak (OLED: typically 1000–2000 nits; mini-LED: 2000–5000+), near-0 nit black on OLED → 1,000,000:1 contrast ratio on OLED.

Bit depth: SDR uses 8-bit per channel (256 levels each of R, G, B). HDR uses 10-bit (1024 levels) or 12-bit (4096 levels) to represent the wider range without visible banding (Mach bands at 8-bit are visible in smooth gradients).

HDR standards:

HDR10: open standard (royalty-free); uses PQ (Perceptual Quantizer) transfer function; 10-bit; static metadata (maxCLL, maxFALL describe the entire content, not per-scene). Supported by all HDR displays and streaming platforms.

HDR10+: Samsung’s open HDR standard with dynamic metadata per scene — allows better tone mapping for each scene’s actual brightness range. Supported on many Samsung TVs, some Amazon Prime content.

Dolby Vision: Dolby’s proprietary format; 12-bit; dynamic metadata per frame; requires Dolby Vision-licensed displays and content. Higher quality than HDR10 in theory; many Netflix and Apple TV+ titles are mastered in DV.

HLG (Hybrid Log-Gamma): broadcast-oriented (BBC/NHK); backward-compatible with SDR displays; no metadata required. Used for live TV and HDR broadcast.

Transfer functions: SDR uses the sRGB transfer function (gamma ≈ 2.2). HDR uses PQ (SMPTE ST 2084) — a perceptually-uniform curve calibrated to the human visual system’s response to luminance, with absolute luminance values (0–10,000 nits). HLG uses a log-gamma hybrid that degrades gracefully to SDR.

Tone mapping: when HDR content with a 10,000-nit range is displayed on a 1000-nit TV, the brightness must be compressed (tone mapped). Different tone mapping algorithms (ACES, Reinhard, filmic) preserve highlight/shadow detail differently. For games, the tone mapper is built into the rendering pipeline; for video, the display or HDR player performs it.

Game HDR: games generate a floating-point frame buffer (FP16) internally; the HDR output path maps the game’s luminance values to the display’s PQ signal. Games that support “Auto HDR” (Windows 11) have HDR conversion applied by the OS for SDR-only games.

Problems:

  • Mastering for HDR: content mastered on a 4000-nit reference monitor looks different on a 600-nit consumer display. Dolby Vision’s per-scene metadata helps; HDR10 doesn’t.
  • HDR in SDR environments: watching an HDR TV in a bright room negates the benefit of OLED’s deep blacks.
  • Content consistency: same “HDR” content looks very different across displays because peak brightness, local dimming, and tone mapping differ.

Why it matters

HDR is the most visible display quality improvement since 1080p. On OLED or high-end mini-LED displays, HDR dramatically changes the viewing experience — highlights in movies and games look real rather than clipped. For developers and engineers: HDR requires specific rendering pipeline changes (FP16 framebuffer, PQ output, tone mapping), colour management, and correct colour space handling. Game developers targeting HDR must implement HDR rendering paths. Platform engineers must implement OS-level HDR support (Windows HDR, macOS EDR).

Real-world examples

  • Netflix serves Dolby Vision HDR to Apple TV, LG OLED, and Samsung TVs; HDR10 as the fallback.
  • Apple’s “Extended Dynamic Range” (EDR) on macOS and Pro Display XDR supports up to 6000 nits for professional HDR reference monitoring.
  • Xbox Series X / PlayStation 5 both support HDR10 and Dolby Vision; most games ship with HDR rendering support.
  • iPhone 15 Pro: 2000 nit HDR display; ProRes video recording in HDR (Log or HLG for post-production flexibility).

Common misconceptions

  • “Any HDR badge means better quality.” Many cheap “HDR” monitors lack local dimming or have insufficient peak brightness; they display an HDR signal but don’t actually render the wide dynamic range. Look for DisplayHDR 1000+ certification or OLED.
  • “HDR is only for movies.” Game HDR, UI HDR (Apple’s EDR for professional use), and medical imaging (radiology, dermatology) all use HDR for different reasons.

Learn next

HDR is closely related to colour management — correct HDR requires accurate colour spaces (Rec. 2020, DCI-P3) and colour-managed rendering pipelines. Anti-aliasing and subpixel rendering address other aspects of display quality.

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