from the all-the-better-for-you-to-see-it-with dept.
VESA has announced the first version of its DisplayHDR specification, which defines standards that displays must meet to be certified by VESA as enabling the use of high dynamic range (HDR). Three tiers are defined: DisplayHDR-400 (low-end), DisplayHDR-600 (mid-range), and DisplayHDR-1000 (high-end). The number is the minimum peak luminance (in nits) that the display must be able to output:
The core of the DisplayHDR standard is a performance test suite specification and associated performance tiers. The three tiers have performance criteria related to HDR attributes such as luminance, color gamut, bit depth, and rise time, corresponding to new trademarked DisplayHDR logos. Initially aiming at LCD laptop displays and PC desktop monitors, DisplayHDR permits self-certification by VESA members, as well as end-user testing, for which VESA is also developing a publicly available automated test tool.
[...] In terms of the first two luminance tests, the minimum 400, 600, and 1000 nit (cd/m2) requirements give the respective DisplayHDR tiers their namesake. At the base level is DisplayHDR-400, which for AnandTech-level enthusiasts is likely to come off as a bit disappointing/unaggressive. To the credit of the VESA, the standard tightens things up over budget LCD monitors and laptops; in particular it requires much higher luminance levels and true 8bpc color support (6+2 is explicitly disallowed). This is coupled with the previously mandatory support for HDR10, and black-to-white response time requirements. However it does not require any "advanced" features,such as the DCI-P3 color space – instead allowing 95% of sRGB – and both the max and min brightness requirements are still quite tame for HDR. Based on the VESA's guidance, it sounds like this is primarily aimed at laptops, where displays are historically power-limited and anything better than global dimming is unlikely to be used.
Moving things up a notch are DisplayHDR-600 and 1000. These two standards are quite similar outside of their maximum luminance, and both are much closer to the requirements many would expect for an HDR specification. In particular, these two tiers require 10-bit color (8-bit native + 2-bit dithering permitted), much lower minimum black levels, as well as having color gamut coverage a minimum of 99% Rec. 709 and 90% DCI-P3. Gamut-wise, VESA mentioned that minimum coverage was essentially tolerance metrics by another name. Of particular note here, while the VESA does not require local dimming for any of the DisplayHDR standards, they note that they don't believe these tiers to be achievable without local dimming, at least not with current LCD technology.
Also at Tom's Hardware.
Samsung and Amazon have announced the HDR10+ open standard:
HDR10+ elevates the HDR10 open standard with the addition of Dynamic Tone Mapping. The current HDR10 standard utilizes static metadata that does not change during playback despite scene specific brightness levels. As a result, image quality may not be optimal in some scenes. For example, when a movie's overall color scheme is very bright but has a few scenes filmed in relatively dim lighting, those scenes will appear significantly darker than what was originally envisioned by the director.
HDR10+ incorporates dynamic metadata that allows a high dynamic range (HDR) TV to adjust brightness levels on a scene-by-scene or even frame-by-frame basis. With the ability to display outstanding contrast with detailed highlights and a richer range of colors, HDR10+ produces images that are much closer to the director's intent.
All of Samsung's 2017 UHD TVs, including its premium QLED TV lineup, support HDR10+. In the second half of this year, Samsung's 2016 UHD TVs will gain HDR10+ support through a firmware update.
Dynamic metadata is a particularly important addition in HDR10+ as it closes the gap between the open HDR standard and the closed Dolby Vision spec, which had previously touted dynamic metadata as one of its main differentiators over the original HDR10 standard. (Although Dolby still leads the pack when it comes to the highest color and brightness requirements, at least for now.) And of course, I'd be remiss in noting that unfortunately, the addition of HDR10+ now marks the fifth major HDR standard vying for industry support, along with the original HDR10, Dolby Vision, HLG, and Advanced HDR, because clearly four different versions were not quite enough for anyone yet.
This morning [January 3] the VESA is rolling out an update to the standard body's DisplayHDR monitor performance standard that's focused on expanding the specification to cover OLED displays. Dubbed DisplayHDR True Black, the new performance tiers to the DisplayHDR standard are intended for OLED and other emissive displays, laying out the levels of display performance that the association believes are appropriate for consumer HDR displays.
This update comes just over a year after the original DisplayHDR standard was launched. Intended to simplify the market for HDR displays, DisplayHDR sets a number of tiers of increasing performance, with each higher tier requiring better monitor technology and delivering a better HDR experience as a result. At the time of DisplayHDR's launch, the VESA opted to focus on LCDs, as these displays were already in the PC market and were what the association had the most experience with. The end result was the DisplayHDR 400, 600, and 1000 standards, which covered a range of monitor designs that essentially stretched from not-very-HDR to cutting-edge full array local dimming displays.
The DisplayHDR True Black update in turn adds two more tiers to the DisplayHDR standard: DisplayHDR 400 True Black, and DisplayHDR 500 True Black. Like the tiers for LCDs, the True Black tiers are divided up based on performance; though the gap isn't quite as big as with the LCD tiers. The end result is that displays reaching these standards, besides meeting the DisplayHDR specification's baseline requirements, can also hit a peak brightness of 400 nits and 500 nits respectively.
The need for separate tiers for OLEDs – and other future emissive technologies like microLEDs – is rooted in the fact that HDR itself is as much (or more) about dynamic range as it is absolute maximum and minimum brightness. While LCDs can offer the necessary contrast ratios with the right backlighting technology, they are still backlit displays, meaning that they can't quite hit black since they're always illuminated to a degree. OLEDs, on the other hands, can hit almost perfect black levels since the pixels can simply be turned off entirely – hence the True Black moniker – which means these displays need to be measured on a different scale. Conversely, while LCDs can sustain incredible 600+ nit brightness levels over the whole screen, OLED technology can only burst to these levels for short periods of time, so the maximum brightness offered by OLED displays isn't quite in sync either with HDR LCDs.
Extremely low minimum brightness seems more useful than blinding maximum brightness. Ergo, any display without "True Black" is junk.
Previously: VESA Announces DisplayHDR Specification