HDR — High Dynamic Range — is the family of video standards that let a TV display a far wider range of brightness and colour than the old SDR (Standard Dynamic Range) world allowed. In practice, that means deeper, more truly black blacks; bright highlights that can hit 1,000–4,000 nits where SDR caps around 100; and a wider palette of saturated colours (typically in bt2020). The result: a sunset that looks like a real sunset, not a tan smear; specular reflections on water that actually feel sharp; deep night scenes with detail in the shadows.
For HDR to work end-to-end, every step of the pipeline has to play along: the camera or mastering tool produces an HDR master, the file is encoded at 10-bit using one of the HDR transfer functions (pq for cinema and streaming, hlg for live broadcast), the streaming server delivers it intact, the TV decodes it and applies tone-mapping to fit the brightness into what the specific display can physically reach. If any link breaks (e.g., a non-HDR TV, a transcoder that strips metadata, a player that doesn't recognise HDR10+ tags), the video plays in SDR or — worse — looks washed out.
Four standards matter commercially in 2026: hdr10 (open, baseline, supported everywhere), hdr10-plus (open, dynamic scene-by-scene metadata, Amazon and Samsung), dolby-vision (licensed, dynamic scene-by-scene metadata, up to 12-bit, the premium streaming default), and hlg (broadcast, no metadata needed, backward-compatible with SDR TVs). For a streaming product launch, the practical answer is usually "HDR10 baseline + Dolby Vision on top" — covers virtually every HDR TV at sensible production cost.
