A few months later at the 2015 CEDIA Expo in Dallas, I saw a fair number of displays being introduced with HDR capabilities. This actually surprised me a little given what is required for a television or projector to truly expand its dynamic range.
To see a greater difference between the darkest and lightest parts of an image, you need a display with high contrast. There are two ways to achieve this – deeper blacks or brighter whites. Of course both would be nice but we all know that’s just not realistic with current display technologies. LCD panels have gone about as black as they’re going to go so to increase contrast, they have to be brighter. Dolby Vision talks about levels of 1000 nits as a minimum for proper rendering of HDR content. To this date, there are exactly zero consumer televisions that can achieve this figure. So how are all these new products supporting HDR?
The fact is that there are no true HDR displays. Support comes in the form of compatibility with a particular standard and sufficient bit depth. Lots of TVs already have 10-bit color, the minimum requirement for HDR. So all a manufacturer needs to do is add HDMI 2.0a and the appropriate firmware to support Dolby Vision and/or HDR10 and boom, they’ve got an HDR TV. Will the picture look better? That depends on your perspective. Actual contrast isn’t any higher but by careful manipulation of gamma, dynamic contrast features and perhaps the addition of zone dimming, it can be convincingly faked.
So rather than launch into an overly-technical discussion of the validity of different companies claims, I thought it would be helpful to provide a quick rundown of just who is doing what in their model lines and what someone shopping for an HDR display can expect to see.
When I visited the Vizio booth at CEDIA last year, I was informed that all R- and P-series TVs would accept Dolby Vision-encoded content. This is made more significant by the fact that these panels have full-array backlights. The Ps offer 126 or 128 zones depending on screen size and the Reference displays have 384. The demos I saw looked stunning and if asked what TV one should buy for HDR right now, I would say a Vizio. While they don’t offer 1000 nits of brightness, they come closer to a true HDR display than any other.
Sony currently has five Ultra HD models in its XBR-series that are HDR-compatible. Ranging in price from $1500 to $8000, these XBR displays use an edge-array backlight unless you go for the top-of-the-line XBR75X940D 75-inch TV which has a full-array backlight though Sony won’t say how many zones there are. They also have a feature called X-tended Dynamic Range Pro which adds an HDR look to SDR-encoded FHD and UHD content. It’s mainly a gamma manipulation, not a true increase of sequential or intra-image contrast. Side-by-side demos look good though and it’s something many viewers might prefer.
Only LG offers OLED panels and they have the potential for greater true dynamic range than any LCD. While they aren’t super-bright, their black levels are truly a sight to behold. Even the best plasma TV can’t achieve the blacks of an OLED. With such high native contrast, OLED panels are a natural for HDR content. LG has added the necessary HDMI 2.0a inputs to their 65 and 77-inch G6P panels which are due to ship this spring. Also significant is their support for both Dolby Vision and HDR10 content. But you don’t necessarily have to buy an expensive OLED TV for this feature. LG’s Ultra HD LCD panels have the same capability and some of the high-end models boast a full-array backlight. But again, there isn’t sufficient brightness nor deep enough blacks to truly expand the TV’s dynamic range.
Samsung is the only manufacturer using quantum-dot technology in its LCD TVs. Quantum dots are a special coating added to the backlight that helps enlarge the color gamut. The dots are microscopic chemical deposits that emit specific wavelengths of light when energized by white LEDs. How does this relate to HDR? Well it won’t increase dynamic range but it will get their S-UHD televisions closer to color gamuts like DCI-P3 and Rec.2020. That has little bearing on currently-available content which is still encoded in Rec.709. Additionally, there are no full-array backlight models in Samsung’s line. So at this time their support is limited to a compatible interface and the 10-bit color depth necessary to display HDR content. But you won’t really see any of the benefits.
Now this is by no means a complete list of HDR displays. But it does show what major manufacturers are currently doing with the technology. Referring back to my longer article, I said that you’d need a 1000-nit panel with full-array backlighting to truly take advantage of HDR. What companies have demonstrated so far is a willingness to support the two major standards, HDR10 and Dolby Vision; and they’ve added the necessary signal interfaces to accept encoded content.
But what’s still missing, and is likely to be for the near-term, is the right display tech. LCDs in their current form aren’t going to cut it. OLED might pull it off but it’ll have to get brighter first. And HDR for projectors is likely even further off in the future.
And there’s the subject of content. We’re only just seeing the first Ultra HD Blu-ray transfers. Ultra HD TVs have been around for three years. So it’s logical to conclude that if 2016 is the first year for HDR displays, we have about three years to wait for the first compatible content to appear. Yes there are a smattering of TV shows in HDR available via streaming right now. But just like UHD streamed content, compression pretty much destroys the benefits.
If you’re shopping for a new television and HDR is something you’d like to check out, make sure you see an in-person demo before pulling the trigger. Checking boxes on a spec sheet is not enough to say a particular display will actually look better than one without HDR. And of course, make sure that enhancements made to SDR content are to your liking.
So my advice, my own opinion, is to wait and see. While I’ve seen some good demos of HDR, none have triggered the “must spend money” response. It’s not so much that the content looks better, it just looks different. A high-contrast display, properly calibrated, showing correctly encoded HD content is still the best ticket to video enjoyment. I’m glad to see the industry moving towards “better pixels” rather than “more pixels.” I just think there’s a ways to go before we get too excited.