HDR10 vs Dolby Vision vs HLG: your chain is only as good as its weakest link

HDR fails in a very specific way: the whole chain silently falls back to standard dynamic range, and you are left with a washed-out picture and no explanation. That is because HDR is a contract between five links - the content, the player or app, the cable, the TV's port, and the panel - and every link must support the dialect being spoken. Diagnosis is therefore the process of finding the one link that doesn't.

The three dialects, plainly

• HDR10 is the baseline every HDR device must speak. If anything in your chain does HDR at all, it does HDR10.
• Dolby Vision adds dynamic metadata - scene-by-scene instructions - and needs licensed support at both ends. A Vision disc on an HDR10-only TV plays as HDR10: fine, but not what the disc intended.
• HLG is the broadcast flavour, designed to degrade gracefully on SDR screens. It is what live TV generally uses, and the least fussy of the three.

Where the chain breaks, in practice

The panel is rarely the weakest link on a modern TV; the breaks are upstream. The streaming app must carry the dialect (an app that only outputs HDR10 will never show Vision). The player or console must have HDR enabled and the format toggled on. The HDMI port matters: on many TVs only specific ports handle the full bandwidth, and a port set to a compatibility mode caps the signal. The cable must be a certified high-speed one; an old cable is a classic invisible break. And any soundbar or receiver passed through must itself pass HDR metadata - an AVR that strips metadata is a single link that downgrades everything behind it.

Finding your weakest link

Work from the screen backwards with one known-good source: play a title you know is Dolby Vision on a device you trust, straight into the TV's best port with a certified cable. If Vision appears, the panel and that path are fine; then reintroduce one link at a time - the soundbar, the other port, the other app - and the link whose reintroduction drops you to SDR or HDR10 is your weakest one. Label the good port and cable so the chain is never accidentally rebuilt wrong.

The payoff for doing this once is that the expensive pixels you paid for - and the distance maths from the 4K-on-a-small-TV piece - are finally showing the dynamic range that was the real upgrade all along.