What are HDR TVs and why you should care

Kris Wouk
Digital Trends
hdr for tvs explained samsung js super uhd tv
hdr for tvs explained samsung js super uhd tv

Samsung JS95000 65″ Super UHD TV

Rich Shibley/Digital Trends

If you’ve shopped TVs recently, you’ve no doubt been seduced by the term 4K UHD (Ultra High Definition). When UHD was first introduced a few years ago, it represented a jump in resolution – basically four times the resolution of 1080p HD. That seemed like a pretty big deal, but we now know that, in 2016, UHD is taking on an entirely new meaning. The very best UHD TVs not only offer higher resolution, but also offer more colors than ever before and something called High Dynamic Range, or HDR.

The idea behind HDR is that it can provide a higher level of contrast between light and dark images on the screen to create a much more realistic image. That may not sound like a lot on paper, but in reality, it’s a pretty significant move. In fact, many in the industry believe HDR represents a significantly bigger leap in picture quality than UHD’s higher resolution. Let’s be clear here: HDR is not the next “3D.” HDR is here to stay, and we couldn’t be happier about it.

Contrast is measured by the difference between the brightest whites and darkest blacks a TV can display, as measured in candelas per square meter (cd/m2), known as nits. The ideal low end is completely black, or 0 nits — currently only possible on OLED displays, which can turn pixels completely off. On the high end, it’s a different story. Standard dynamic range TVs generally produce up to 300 to 500 nits, but some HDR TVs aim much, much higher.

120" VIZIO Reference Series
120" VIZIO Reference Series

120″ VIZIO Reference Series

Vizio

Multiple formats for displaying HDR are possible, but currently there are two major players: Dolby Vision and HDR10. Dolby was first to the party, displaying a prototype TV capable of displaying up to 4,000 nits of brightness. For a short time, Dolby Vision was essentially synonymous with HDR, but not every manufacturer wanted to play by Dolby’s rules, and many started working on their own alternatives. Companies quickly realized that this could lead to madness, and many popular manufacturers, including LG, Samsung, Sharp, Sony, and Vizio eventually agreed on an open standard, HDR10.

Related: Samsung UN55KU7000 4K Ultra HD TV Review

In April, the UHD Alliance — an inter-industry group made up of companies like Samsung, LG, Sony, Panasonic, Dolby, and many others — announced the Ultra HD Premium certification for UHD Blu-ray players. This benchmark sets some baseline goals for HDR, like the ability to display up to 1,000 nits of brightness and feature a minimum of 10-bit color depth. Both HDR10 and Dolby Vision meet the standards set by the certification, but how they go about it varies greatly between the two.

HDR10

While Dolby Vision may have been first, it isn’t currently the most popular format. Instead, the current most popular format is HDR10, an open standard backed by companies including Samsung, LG, Panasonic, and Hisense, who also happens to own the rights to the Sharp brand name for TVs in the U.S. It isn’t as technologically advanced as Dolby Vision’s theoretical specs, but then again, neither are the Dolby Vision-enabled TVs you can go out and buy right now.

The HDR10 standard currently uses 10-bit color, while Dolby Vision uses 12-bit color depth. Both of these offer millions of colors per pixel, and the difference will difficult to spot depending on how a given movie or TV show is mastered. Since one of the goals of HDR is to offer greater color volume, a higher color depth is desirable, at least in theory, but even 10-bit color depth is a major step up from the 8-bit color depth used in standard dynamic range TVs.

Both of the two major HDR formats in use today use metadata which rides along the video signal down an HDMI cable, and allows the source video to tell TVs how to display colors. HDR10 uses a fairly simple approach, sending metadata once at the start of a video. This is enough to essentially tell the TV “this video is encoded using HDR, and you should treat it that way,” but as we’ll see later, Dolby Vision takes a different and more complex approach with how it uses metadata.

While HDR10 plays it more safe than Dolby Vision when it comes to technology, it is also more feasible for TV manufacturers to implement right now, rather than in the future, so it has become the more popular of the two formats. This is also helped by the fact that HDR10 is an open standard — TV manufacturers can implement it freely. It is also recommended by the UHD Alliance, which generally prefers open standards to proprietary formats like Dolby Vision.

Related: Everything you need to know about Ultra HD Blu-ray

Dolby Vision’s proprietary nature means that manufacturers need to pay Dolby in order to use the technology in their TVs and UHD Blu-ray players, the latter of which has yet to be done. Even TVs that originally shipped with only Dolby Vision should be able to add HDR10 support via a firmware update.

Dolby Vision

HDR10 might currently be in more TVs, but that might not necessarily always be the case down the road. In terms of sheer technological might, Dolby Vision has a clear advantage, even with TVs available today. Looking toward the future, the gap between Dolby Vision and HDR10 becomes even more apparent.

hdr for tvs explained dolby vision train
hdr for tvs explained dolby vision train

Dolby

hdr for tvs explained dolby vision cave
hdr for tvs explained dolby vision cave

Dolby

hdr for tvs explained dolby vision water
hdr for tvs explained dolby vision water

Dolby

hdr for tvs explained dolby vision buildings
hdr for tvs explained dolby vision buildings

Dolby

As mentioned earlier, Dolby Vision offers 12-bit color depth, as opposed to the 10-bit color depth offered by HDR10. It also offers higher theoretical brightness. HDR10 currently maxes out at 1,000 nits, while Dolby Vision can currently handle 4,000 nits, with Dolby saying that future upgrades to its tech could allow it to handle up to 10,000 nits of maximum brightness. Current displays can’t display anywhere near that, but that won’t always be the case.

Color depth isn’t the only area where Dolby Vision has a theoretical advantage over HDR10. As mentioned above, HDR10 only transmits metadata once,when a video starts playing. Dolby Vision, on the other hand, uses dynamic metadata, which can vary per scene or even on a per-frame basis. Again, the advantages here are mainly theoretical right now, but as content providers become more adept at mastering for HDR, dynamic metadata could prove to be a major advantage.

The Dolby Vision spec also allows the screen displaying a video to know about the screen used to master the scene, and can automatically account for the differences between the two displays. This leads to an image that is automatically adapted to fit the best it can to your individual display, rather than relying on assumptions made by the mastering engineer.

HDR10 might currently be better supported, both in terms of TVs and content, but Dolby is hard at work trying to change that. Currently, Vizio and LG are the only two manufacturers that offer support for both Dolby Vision and HDR10.

Other contenders

Dolby Vision and HDR10 are currently seen as the two big players when it comes to HDR, but that doesn’t mean that there aren’t other companies trying to solve the problem in different ways. There are two other emerging formats, both of which aim to make backward compatibility with standard dynamic range (SDR) a major focus.

Hybrid Log Gamma (HLG) is a format from the BBC and Japanese broadcaster NHK. As the two organizations behind the format may hint, HLG has been developed with a focus on live broadcasting, though it can also be used for pre-recorded content. Unlike HDR10 and Dolby Vision, HLG doesn’t use metadata, which could be an advantage, depending on how TV manufacturers implement it.

Technicolor was an early player in HDR, and at CES 2016, the company announced that it and Philips had merged their efforts in HDR and were working on a new format. Like HLG, this format would aim to be backward compatible with SDR displays, which the companies said in a press release “will simplify HDR deployments for distributors who will be able to send one signal to all of their customers, regardless of which TV they have.”

So, what do we watch? (The content conundrum)

Even if your TV has the latest and greatest HDR, color reproduction, and 4K UHD tech, much of what you watch won’t be able to take advantage of all that awesome. Hollywood, of course, is working quickly to remedy this issue, but HDR content is currently on the limited side, even more so than 4K. Below are a few of the easiest and most available ways to get started.

Ultra HD Blu-ray

Offering the highest-quality delivery method for a top-quality HDR experience at home, UHD Blu-ray allows for 4K UHD resolution, HDR and color expansion, and revolutionary new surround sound codecs like Dolby Atmos, and DTS:X. The recent update to HDMI 2.0a was essentially based entirely around clearing the way for High Dynamic Range devices, including new Blu-ray players, and other set-top devices.

As with other delivery methods, Ultra HD Blu-ray releases with HDR are currently somewhat limited — somewhere around 50 titles as we write this —  but most studios have pledged to significantly increase their output of HDR releases over the course of the next year. HDR10 is currently the only format available, as no Ultra HD Blu-ray player on the market features Dolby Vision support, but this could change in the future.

Netflix

As a major provider of video, it probably comes as little surprise that Netflix was one of the first companies to announce it would support HDR. That made it somewhat strange when the company quietly rolled out HDR on Marco Polo (a title that it had announced would be getting HDR) without notifying anyone.

Marco Polo has been joined by a number of other Netflix Originals, including Marvel’s Daredevil, Jessica Jones, and Luke Cage, as well as movies like The Do-Over and The Ridiculous Six. HDR titles from Netflix are available in both HDR10 and Dolby Vision formats.

Amazon

Like Netflix, Amazon announced fairly early on that it would be offering titles in HDR. A number of movies including Fury, Elysium, and The Amazing Spiderman 2 are available via Amazon Prime Video. Amazon also provides much of its original programming in HDR. Shows featuring HDR include Man in the High Castle, Transparent seasons 1 and 2, Mozart in the Jungle seasons 1 and 2, Bosch, and Red Oaks. It’s likely that most if not all of Amazon’s future original programming will also be available with HDR.

Amazon initially only supported HDR10, but in June of 2016 the company added support for Dolby Vision. At the time, the company said that more titles were available in HDR10, with a subset available with Dolby Vision, but added that it planned to offer more than 150 hours of HDR content in both formats by the end of 2016.

Vudu

One of the earliest providers of 4K programming, Vudu was also quick to offer HDR support. The service offers one of the largest libraries of 4K movies and TV shows available for rent or purchase, and many of them are available with HDR as well as Dolby Atmos object-based surround sound.

Currently, Vudu’s HDR offerings are only available in Dolby Vision. This looks like it could change in the near future, however, as the company recently said in a statement to Forbes that it expected to add support for HDR10. When exactly this might be is still up in the air.

What about gaming?

While most guides focus on passive viewing experiences while talking about HDR, game consoles are quickly becoming an important part of the discussion. With the PlayStation 4 Pro and Xbox One S, Sony and Microsoft have thrown their respective hats into the the HDR ring, but it can be a much more complicated to access all that sparkly goodness than you might expect.

Xbox One S

We’re kicking off with Microsoft’s update to the Xbox One because it’s a much simpler story overall. While the first-generation Xbox One didn’t feature support for either 4K or HDR, the revamped version features both. In addition to 4K support, complete with HDMI 2.0a and HDCP 2.2, HDR10 is supported for both games and general entertainment purposes, though the other competing standard, Dolby Vision, is not.

Xbox One S
Xbox One S

Bill Roberson/Digital Trends

Streaming in HDR is currently limited to Netflix, but other streaming services are upscaled to 4K. Microsoft has even taken things a step further by including an Ultra HD Blu-ray drive built-in, meaning you get twice the bang for the buck — especially considering that the Xbox One S is priced competitively with many UHD Blu-ray players currently on the market.

The system does not, however, support native 4K Ultra HD content for gaming. Instead, video is upscaled to 4K. On the bright side, HDR is supported for a number of games, including Battlefield 1, Gears of War 4, and Forza Horizon 3.

PlayStation 4 Pro

Unlike Microsoft’s first effort, Sony did add HDR to the original PS4, but without 4K Ultra HD support. That means it won’t be very helpful as a streaming device for HDR, especially since apps like Netflix and Amazon currently only support HDR alongside 4K. The HDR support on board here will only be useful for a select number of games which include HDR, though more are expected to roll in soon.

Like the Xbox One S, the PlayStation 4 Pro features HDMI 2.0a and HDCP 2.2, and supports HDR10 but not Dolby Vision. This allows the PS4 Pro to supports both 4K and HDR, but currently there isn’t any way to watch anything in HDR, as the Netflix apps for Amazon and Netflix don’t support 4K or HDR. For now, it’s only useful for gaming.

Unlike the Xbox One S — and this is key for home theater enthusisasts — Sony didn’t include a UHD Blu-ray drive in the PS4 Pro. That’s somewhat of a surprise considering how much the built-in DVD drive drove sales of the PlayStation 2, while the PlayStation 3 helped Sony’s own Blu-ray format win the high definition hardware war over HD-DVD.

ps4-pro
ps4-pro

While native 4K gaming isn’t supported on the Xbox One S, it is possible on the PS4 Pro, though it’s a complicated situation, as some games are native while others are upscaled. HDR gaming is supported for a variety of titles, including Uncharted 4: A Thief’s End, The Last of Us: Remastered, Thumper, and many more.

Then there’s the VR complication. Sony has also focused heavily on virtual reality with its PSVR hardware, but this presents a problem for those who would like to game in HDR, as the two are currently mutually exclusive. “If you’re playing a normal, non-VR game on your PS4 Pro, PS VR’s Processor Unit will output a 4K signal to a 4K TV,” Sony blog post reads. “The Processor Unit does not support HDR pass-through,” the post continues, meaning you’ll have to go directly into the TV from the PS4 Pro to view HDR content.

That is less than ideal, but both consoles are dealing with their fair share of issues related to 4K and HDR. As time goes on, bugs will likely be worked out, though it remains to be seen if anything to fix the issue with PSVR is even possible.

So there you have it. High Dynamic Range is a lot more complex than just three little words. But it’s also a very exciting technology that will pull us even deeper into the spectacular movies and TV series we love to watch, creating more brilliantly realistic images than ever. If you’re wondering if the next TV you buy should be HDR compatible, our answer would be: Yes. HDR is the most meaningful upgrade to the home video viewing experience that we’ve seen since the introduction of the Plasma TV and the jump to high definition, and it’s definitely at the core of television’s future.