HDR formats explained: HDR10, HDR10+, Dolby Vision and HLG
Four HDR formats, doing the same job in different ways. What separates them is metadata and licensing rather than picture quality — and a television that supports HDR can still show it badly.
High dynamic range is the most consequential change to television pictures since the move to high definition, and the most poorly explained. It is not a resolution, it is not a single standard, and buying a television that lists it is not the same as being able to see it.
What HDR actually changes
Conventional television — now retrospectively called standard dynamic range — was built around the limits of the cathode ray tube. The brightness range it could describe was narrow, and everything from cameras to broadcast standards was designed around that ceiling.
HDR widens two things at once: the range between the darkest and brightest parts of an image, and the range of colours available. The practical result is not a brighter picture overall but a picture with more headroom — specular highlights that stay bright while shadow detail survives, rather than both being flattened toward the middle.
The four formats
The formats differ mainly in what metadata they carry — the instructions telling a display how to map the content's brightness range onto its own.
| Format | Metadata | Licensing | Typically found |
|---|---|---|---|
| HDR10 | Static — one instruction for the whole title | Open | Universal baseline; every HDR set supports it |
| HDR10+ | Dynamic — per scene | Royalty-free, requires certification | Samsung sets, Prime Video, some discs |
| Dolby Vision | Dynamic — per scene, up to per frame | Licensed from Dolby | Widely licensed across sets and services |
| HLG | None — backwards-compatible signal | Open | Broadcast, where one signal must serve both HDR and SDR sets |
Why dynamic metadata matters
A film may contain a dim interior and a bright exterior. With static metadata the display receives one set of instructions covering the whole title, so it must compromise across both. With dynamic metadata it receives instructions per scene and can adapt.
The difference is largest on displays that cannot reach the brightness the content was mastered for — which is most of them. On a set that can reproduce the full range, the formats converge.
HLG is the odd one out
Hybrid Log-Gamma was designed for broadcast, where a single transmission has to serve HDR and SDR sets simultaneously and there is no opportunity to send metadata alongside. It solves a distribution problem rather than a picture-quality one, which is why it appears in broadcast contexts and rarely on streaming services.
Why HDR sometimes looks worse
This is a common and legitimate complaint, and it usually has one of three causes.
- The display cannot reach the brightness the content assumes. It must tone-map down, and an aggressive mapping can crush shadow detail — producing a picture that is dimmer and murkier than the SDR version.
- The room is bright. HDR's advantage is largest in a dark room. In daylight the extra shadow detail is invisible and the lower average brightness is not.
- The set switched picture mode. Many televisions change mode automatically when an HDR signal arrives, and the HDR mode may not be the one you had calibrated.
What to check
- Which formats the set decodes — HDR10 is guaranteed; Dolby Vision and HDR10+ are not, and few sets carry both.
- Which formats your services publish in, since that is what determines whether the support is used.
- Peak brightness and local dimming, which decide how much of the format's range is actually reproducible.
- The connection. HDR at high resolutions and frame rates has bandwidth requirements over HDMI.
Broadcast HDR delivery is covered in ATSC 3.0 and NextGen TV. Terms are defined in the glossary.
Sources and further reading
- Dolby — Dolby Vision technology · The licensor's description of dynamic metadata
- ITU — Recommendation ITU-R BT.2100 — HDR-TV parameter values · The standard defining the HDR transfer functions, including HLG
Written by
MobilizedTV Editorial Team
MobilizedTV is written and edited as a single publication rather than by named individual contributors. How we research, source and correct our work is set out in the editorial policy.
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