Here’s why HDR in 4K TVs is awesome and here to stay
Stephan Jukic – August 18, 2016
Now that 4K TV technology has gone fully mainstream and continues to grow its market share, a whole new development in these cutting edge televisions is being fleshed out in the form of high dynamic range (HDR).
And while it still has plenty of users confused about its details (partly because even the manufacturers themselves haven’t gotten their standards on HDR settled yet), those who’ve seen HDR in action are rightfully and powerfully impressed or the most part, us included.
Unlike 4K resolution, which is only really appreciable on larger 55 inch+ TV displays at closer distances, HDR in a piece of display technology is immediately visible at any distance and any size, as long as the content being shown is also formatted with high dynamic range meta data. We’ve already covered HDR in heavy detail in our guide to the technology, which you can check out here, but for more brevity and a couple new details, here is a quick breakdown of exactly why HDR is the real powerhouse technology of all major high quality 4K TVs and eventually 8K as of now.
At its core, HDR is more than anything about the concept of “better pixels” and the technologies that go into high dynamic range focus on these heavily. While 4K was aimed at filling your TV or PC or even tablet and projector screens with more pixels than ever before, HDR makes those pixels work much more realistically and vibrantly than they ever did before with SDR (standard dynamic range) TVs and content.
And “better pixels” isn’t just some empty marketing phrase, in the case of HDR it truly does apply in terms of color, vibrancy, contrast, black levels and realistic brightness, along with all the variations in each of these categories which make a TV display and a piece of HDR content simulate reality as closely as possible in any given moment.
Color in HDR
For starters, HDR TVs and content mean the delivery of better color saturation. Instead of the faded, washed out colors found in most SDR TVs, high dynamic range mixes RGB colors as accurately as possible and then actually displays their dense information in a way that essentially produces colors much more like those we actually see with our eyes in the real world. When viewing an SDR 4K TV display next to an HDR 4K display, the difference is stunningly notable and in the case of HDR color saturation, the wider coverage of an uncompressed color space means reds, blues and greens on even simple things like coke bottles, gold courses and skies which resonate with some very impressive realism.
Secondly, the chromatic resolution of HDR TVs is much broader and this translates to a far larger range of complex color blends which also works to further augment content realism. In contrast to 8-bit SDR TVs, today’s 4K HDR models come with what is called 10 bit color. The difference may seem small at first glance but due to mathematical compounding, those two extra bits result in a vastly expanded range of color values.
Quite simply, with an 8-bit SDR TV, each RGB color comes with 8 bits of color memory, allowing for 256 different variations per individual red, green and blue pixel color. This amounts to a total of 16.8 million possible colors if all three RGB colors are combined in different permutations.
In contrast, HDR 10-bit color and its 2 extra bits of color memory per RGB color amount to 1024 different color variations for red, green and blue. Blending all three together in different ways results in over 1.07 billion colors instead of 16.8 million.
This of course means a much more finely graded color range as well, with extremely smooth transitions from one tone to another and a resulting level of realism which is much more in line with how a normal human eye sees the real world.
Darkness and Brightness
The next major pillar of high dynamic range is the range between bright and dark that it can produce. We go into detail on both of these specs in our HDR guide but the bottom line is that quite simply, HDR TVs can produce much deeper, richer blacks while also producing much brighter, more realistic bright spots and to top things off, they can deliver a much finer range of brightness steps in between the two extremes.
The differences these two extremes of brightness and darkness in HDR TVs create is possibly the single most visibly stunning aspect of this technology and with the latest high dynamic range TV models from brands like Samsung, peak brightness levels of 1400 nits or more can be delivered while black levels of .0.2 nits are also possible. In OLED 4K TVs with HDR built into them, the contrast range is even more extreme since OLED technology can produce perfect, total blacks while now delivering stunningly high (by OLED standards) peak brightness levels of 600 nits or more in the latest 4K OLED TVs, like the LG E6, for example.
In contrast, a typical SDR 4K TV can manage a maximum of maybe 300 nits of brightness and in the case of LCD 4K SDR TVs, very greyed out black levels of 0.7 nits are quite common, completely ruining such TVs ability to deliver the sort of inky dark scenes which really emulate reality on a digital screen. For older SDR HDTVs, things were even worse, with many models being capable of delivering no more than 100 to 150 nits of maximum brightness, more than 10 times less than what a high-end 4K TV with high dynamic range is capable of.
More importantly still, the formatting of HDR content, especially Dolby Vision HDR formatting in content is set to accurately and precisely reach peak brightness levels which go even higher than those above. Thus, many movies and shows which have been mastered for HDR today are already prepped for 4000 nits or even more of brightness, as soon as HDR TVs capable of reproducing these levels emerge (and they are coming, sooner or later).
In even more practical terms, these high and low extremes of bright and dark result in stunning movie scenes where the sparkling of chrome in the sin leaps right out of the screen and where stars in a night sky truly seem to sparkle in their ink black surroundings, both extremely faithfully recreated on an HDR display through HDR content encoding. The realism these developments deliver is something which has to be seen to be believed because it completely blows old TV display standards for quality right out of the water.
The Bottom Line
HDR isn’t just a fad and it isn’t going away either. This technology is absolutely here to stay and it will be the de facto standard of all new 4K TVs (and possibly HDTVs as well eventually) in the coming years. It will also translate itself to 8K TVs when they start going on sale in the next few years. The only things which will change are further refinements and expansions in the quality/range of HDR and of course, prices for 4K TVs with the technology.
Already, many of the superb high dynamic range TV models for 2015 and 2016 are remarkably affordable and this price drop will continue, just as it did with conventional 4K TVs between their emergence in 2013 and today. The same applies to HDR content, it will only become more numerous and at some point it will also be the dominant type of premium digital home entertainment video on the market.
You can of course wait to buy a 4K HDR TV until content choices and display capacities with this technology mature even further but the if you want the best possible home entertainment experience available today, the existing high dynamic range models on the market are more than impressive enough, particularly if you’re moving from an ordinary HDTV to an HDR model with 4K UHD resolution.
Story by 4k.com