High Dynamic Range ( HDR ) has now been with us for some time, we have new more advanced versions now available on selected Televsion models.
Standard HDR10 uses static metadata, which means the boundaries of brightness are set at the start of a film or show and don’t change for the duration of that show or movie.
These boundaries have to be broad enough to display every scene of the film essentially, the TV’s 1.07 billion colours are spread evenly across that entire brightness spectrum, which means that if a scene contains only bright or only dark elements, only a portion of those colours are available for it. This can result in dark scenes looking a bit dim and bright scenes losing detail.
With dynamic metadata, those brightness boundaries can be set and changed on a frame-by-frame basis, so the full colour range can be deployed even in scenes that contain only dark or only light elements. The result, in theory, is subtler gradients and therefore more detail.
HDR10+ and Dolby Vision are similar in that they both use dynamic metadata to tweak a TV’s performance to get the most out of every frame,but there are key differences.
TV manufacturers and studios have to pay Dolby to license Dolby Vision, and therefore have little control over its development and implementation, HDR10+ is a free open format that any company can tweak and deploy as it sees fit.
Dynamic metadata for HDR10, HDR10+ carries over the limitation to 10-bit colour depth. Dolby Vision goes up to 12-bits making it capable of reproducing billions more colours.
With 12-bit TVs still a fantasy, this isn’t a big deal yet,but when they do finally become reality this could be a big differentiator. Of course there’s every chance that new, open formats (HDR12 and HDR12+) will also arrive at that time.