Thinking about buying a new Ultra HDTV? You might want to wait a few months…or maybe a year. HDR is coming!
I know, I know. It seems like the new TV you just bought is already obsolete (although it really isn’t; just a little behind the times.) You can’t keep up – first, it was 720p plasma, and the market move to 1080p. Then it was 1080p LCD, followed by super-thin LCD televisions. Then “smart” TV and 3D (although the latter died a quick, merciful death).
And now, it’s Ultra HD. And OLED TV. When will it stop? Answer – it won’t, not with overcapacity for panel manufacturing in Asia and plummeting retail prices for bigger screens. In fact, as I’ve pointed out numerous times before, Ultra HD and Full HD televisions have essentially reached price parity. In many cases, an extra $100 will buy you Ultra HD resolution in the same screen size. Or $50 will get you an Ultra HDTV with five fewer inches of screen size.
The way things are heading, your next television purchase is almost certain to be an Ultra HDTV, provided it’s 50 inches or larger and you buy it no earlier than December. By then, prices will have fallen so much on UHD models that it wouldn’t make any sense to invest in a newer Full HD model. Not only that, but retailers are already allocating a larger percentage of inventory to Ultra HDTVs, cutting back on the number of Full HD models they stock.
There’s another reason you’ll want to wait until December (or later) to pick up a new Ultra HDTV, and that’s HDR – or, more specifically, high dynamic range.
HDR is the latest enhancement to come to television. Unlike 3D, you don’t need any special eyewear to see it. And the difference between standard televisions and HDR sets is dramatic – much brighter whites and higher contrast ratios on LCDs, greater shadow detail and brighter highlights on OLEDs. In other words, television pictures that approximate what your eyes see every day.
In the world of photography, we measure exposures in “stops” of light, like f2.8, 4, 5.6, 8, etc. Think of standard dynamic range as something in the range of 8 to 10 stops. In comparison, HDR can represent a minimum of 15 stops of light, with each additional stop being twice as bright as the previous one. (Some advanced HDR cameras can capture 20 stops of light!)
It’s hard to describe the concept of HDR with words, but trust me; when you see it, you’ll know it. Combined with Ultra HD resolution, it is an entirely new TV viewing experience than anything you’ve seen before. Even plain vanilla Full HDTV looks different with HDR content.
HDR has become such a big deal that a good portion of the Day 2 session at the recent Hollywood Post Alliance Technology Retreat was devoted to this topic, with a couple dozen speakers covering all aspects of capture, post, mastering, and distribution to the home. And to be honest, not many of these experts know how it will all work in the end, especially when it comes to the consumer viewing experience.
So, what do you need to watch HDR? First off; your TV must have some way of reproducing the high dynamic range signal, which means the basic white LED backlight with color filters used by just about every garden-variety LCD TV won’t work. Instead, you’ll want to look for LCD televisions using enhanced backlighting technology like quantum dots.
Quantum dots (QDs) are tiny nanocrystalline chemical compounds that emit high-intensity color light when stimulated by photons, usually from blue or ultraviolet light sources. (That’s the “quantum energy” effect.) Several different companies manufacture quantum dots – QD Vision makes them in light pipes for thin LCDs, while Nanosys and 3M have joined forces to produce a QD film layer for LCD displays.
Presently, Samsung (S-LCD), Vizio, and Sony (certain Triluminous models) sell Ultra HDTVs with quantum dot technology, and are soon to be joined by TCL and Hisense. LG has also shown LCD TVs with quantum dot technology, but they have a trick up their sleeve – organic light-emitting diode (OLEDs) televisions.
OLED technology can also reproduce HDR signals. LG’s white OLED emitters work with color filters in a red-green-blue-white stripe to achieve high brightness and strong color saturation, easily achieving the 15-stop threshold. While OLEDs can’t hit the peak brightness levels of HDR LCDs (800 nits or more), they do much better coming out of black and reproducing very low luminance steps – something that LCDs can’t do without tricks like dynamic backlight dimming and contrast/black level manipulation.
At the 2016 CES, the Ultra HD Alliance released their specifications for “premium” Ultra HD, a/k/a HDR. The sets must have a minimum resolution of 3840×2160 pixels and reproduce HDR signals using the SMPTE ST2084 standard, with 10 bits per pixel minimum. (The current Blu-ray format, along with broadcast cable, satellite, and streaming TV services, relies on 8-bit color formatting.)
For LCD Ultra HDTVs, the specification calls for a level of black no higher than .05 nits (it can be lower) and a minimum brightness of 1000 nits. For OLED TVs, the black level must be .0005 nits (no higher) and white has to hit 540 nits. If you‘re interested in the resulting contrast ratios, it would be 20,000:1 for LCDs and over 1,000,000:1 for OLEDs.
Hand-in-hand with HDR is a new, wider gamut of colors (WCG) known formally as ITU Recommendation BT.2020. The “2020” color space is quite a bit larger than the current ITU Rec.709 color space that came into use with digital TV. With this new space, you’ll see brighter, more saturated greens and reds and over a billion shades of color. (8-bit color is limited to 16.7 million shades.) And to reproduce those shades of color, you need more horsepower under the hood. (Hence; quantum dots and OLEDs.)
What about content? New standards have been released for HDR Blu-ray discs that follow the UHD Alliance Premium specs – 10-bit color, 3840×2160 resolution, and BT.2020 color space representation. In the Samsung booth at CES, a shelf display contained more than 100 Blu-ray movie packages that have been or will be mastered with HDR and WCG. Some of those titles are available now to play back on Samsung’s UBD-K8500 player ($350) or Panasonic’s DMP-UB900 (no price yet). Expect BD players from LG and Sony to make an appearance this year, too.
But the question now is the relevance of optical media. Numerous studies have shown that rentals of Blu-ray discs have been in decline for some time, and BD sales don’t make a dent in the ever-growing volume of transactional video-on-demand, streaming, and digital downloads.
The good news is that HDR content can be streamed or downloaded, although your Ultra HDTV or media player will likely require support for a new video compression/decompression (codec) standard, High Efficiency Video Coding (HEVC) H.265. Many new Ultra HDTVs support this standard. Google’s VP9 and VP10 codecs, used with YouTube 4K content, may also support HDR in the future.
And what about flavors of HDR? Right now, the system getting the most attention is Dolby Vision, which got out of the gate early and is now implemented on Vizio, TCL, Sony, and Philips HDR LCD Ultra HDTVs. LG announced at CES that they would also support Dolby Vision on their premium Ultra HD OLED TVs. Another system has been proposed by Technicolor and it appears that TV manufacturers will support it as well.
The trick is compliance with the CTA 861.3 standard for reading and understanding HDR “metadata” that will be encoded with the HDR movie or TV program. This metadata will travel through the HDMI or DisplayPort interface in what’s called an “info frame” and the Ultra HDTV should reproduce it correctly. For streaming content, HDR metadata will be embedded in the program and read by the TV on the fly.
At CES, both Samsung and LG showed HDR Ultra HD content as a broadcast signal, using the new ATSC 3.0 standard and a UHF TV channel. Not many people paid much attention to this demo, but it was significant that HDR content can be broadcast as well as streamed. Yet another HDR format, hybrid log gamma, has been proposed by the BBC and NHK as a way to transmit one signal with both SDR and HDR content, letting the compatible Ultra HDTV show it in the appropriate format.
We already have several precedents for this piggy-back backward-compatible approach, such as the NTSC color “burst” signal added to black-and-white television transmissions in the 1950s and the FM stereo sub-carrier that also appeared in the late 1950s. Viewers with older Ultra HDTVs (which wouldn’t be that old, trust me) would simply see an SDR signal, while newer sets would expand the dynamic range at the high (brighter) end to achieve HDR.
Now, a lot of what I’ve just described is still in the building stages. Only a handful of HDR Ultra HDTVs are available right now, and only Samsung’s HDR Blu-ray player is on store shelves. I don’t know of any streaming content providers that are formatting programs in HDR, although Netflix and Amazon Prime are streaming 4K video. There aren’t any 4K cable channels at present, nor are any broadcast networks transmitting 4K shows.
But they’ll all catch up over time. They key is to have an Ultra HDTV that supports HDR and WCG playback, preferably one with both HDMI 2.0a (HDR) and DisplayPort 1.4 inputs. The former interface is already supported, although on a limited basis, while the latter was just announced a week ago.
And that brings me back to my original premise – if you are considering the purchase of a new Ultra HDTV, you’d be smart to wait until the end of the year or even until mid-January when TV prices are historically their lowest. And check to make sure your new set supports HDR through ALL inputs, not just the HDMI connection.
By then, you’ll have a much larger menu of HDR content choices, and of course you can still enjoy watching SDR 4K content. (And by then, you’ll see that big-screen Full HD sets have largely disappeared from store shelves anyway!)
The post “HDR” Is Coming To Your Next TV. So What, Exactly, Does That Mean? appeared first on HDTVexpert.
Posted by Pete Putman, March 7, 2016 9:21 AM
About Pete PutmanPeter Putman is the president of ROAM Consulting L.L.C. His company provides training, marketing communications, and product testing/development services to manufacturers, dealers, and end-users of displays, display interfaces, and related products.
Pete edits and publishes HDTVexpert.com, a Web blog focused on digital TV, HDTV, and display technologies. He is also a columnist for Pro AV magazine, the leading trade publication for commercial AV systems integrators.