On January 9th at CES 2014 at The Venetian, I was invited by Craig Eggers of Dolby Labs to witness a finished product of Dolby VISION imaging technology which was first mentioned at the Dolby booth in Las Vegas Convention Center about half a decade ago. Instead of opening this show to the public, Dolby invited a few technology journalists to see a first look (but completed) preview of a technology Dolby hopes will revolutionize the consumer display business.
While Dolby is best known for its advancements in sound technologies (Atmos, a 64-channel surround system being their latest innovation), the company realizes sound is only half the experience. This is the reason that a few years ago, they developed the Professional Reference Monitor, or PRM, for post production and professional colour grading. They’ve also joined forces with the Cameron Pace Group to design glasses-free 3D display technology (which is, at present, is not part of Dolby VISION Imaging Technology). Of course, Dolby has been experimenting with better codecs, bit rate efficiency, as well as the rumoured 32-channel version of Dolby Atmos for home use.
According to Dolby (and I might add, very accurately) if one wants to make TV better, then it is about:
• Higher resolution
• Higher pixel speed and frame-rate
• Higher pixel quality (in their ability to have better native contrast.
Over a series of focus groups and experiments, Dolby learned people preferred images that were 200 times brighter than current TV standards of 45 foot-Lambert, and with 4,000 times more contrast.
In short, Dolby thinks the keys to better TVs are brighter pixels as well as pixels with a much higher native contrast.
What are “NITS”?
Before I can talk about the demo and jump into Dolby’s new high dynamic range imaging technology, we need to be on the same page about the current standards and a few necessary glossaries.
The first such term is a Nit, which is a measurement of light (similar to, but quite different from a foot-lambert). One Nit = one candela per square meter, which doesn’t really help define a Nit. So here are some real world scenarios: if you look up directly at the sun, your corneas are looking 1.6 billion Nits (and will be blinded permanently shortly afterwards). A typical skylight lets in about 100 million Nits. A flourescent light emits about 4,000 Nits. Black asphalt on a sunny day, reflects about 2,000 Nits. And all the way down at the very bottom of the spectrum, we have the distribution infrastructure for cinema projectors and CRT televisions.
Cinemas (when projected properly) only come up to 50 Nits, where broadcast TV and Blu-ray top out at 100 Nits.
All of this to say, filmed entertainment, when displayed in cinemas and in the home, isn’t exactly lifelike in terms of brightness levels. For example, have you ever taken a photograph inside a room where there are a lot of windows? Your eyes can see inside and outside perfectly, but with the camera, you’re either going to “blow out” the windows, or by seeing outside, everything inside is too dark. Essentially, current generation displays are limited to make similar choices in terms of brightness levels and contrast.
Why does it matter?
When you reduce brightness and dynamic range, you also rob yourself of reproducing certain colours. Check out these three slides of the various colour spectrums (photos taken with my BlackBerry Q10 which turns out to have a faulty lens, so my apologies for the severe lack of quality). The entirety of the visible colour spectrum (what we can see) is the outer line. In each corner, you have Red, Green, or Blue. Somewhere in the middle, with enough of each colour, you get “pure white.” The first triangle inside All Visible Colours is called the “REC2020” standard, which represents all the colours reproducible by an upcoming laser projection technology. Note how many colour information disappear from what we can actually see:
Then we have the “P3” standard, which represents all the colours reproducible in film (and digital cinema). We’ve lost even more:
Finally, we have the “REC 709” standard, which represents all the colours Blu-ray currently reproduces:
What does it mean?
Blu-ray marks the best home entertainment distribution format currently available, yet it turns out Blu-ray’s colour spectrum is so limited that anytime you see a green highway sign, or the Canadian flag, the colours are incorrect. That’s right, those particular shades of red and green do NOT exist in REC 709 Blu-ray, so the filmmakers — when colour grading / timing for Blu-ray (and broadcast TV) — have to cheat, but in doing so, brightness levels and contrast suffer. Meaning, when they find a replacement green or red, it’s often much closer to white on the colour spectrum and, when compared to the original uncompressed RAW footage captured during production, much more washed out. Of course, subsequently, when colours wash out, you are losing fine detail and apparent resolution.
At this point, we know TV and film are pretty limited in terms of accurately reproducing contrast and colours, but to demonstrate what this means for perceived picture quality, it was time for Dolby’s demo.
In a room perfectly devoid of light, we watched HD footage shot on the ARRI Alexa digital cinema camera. The first part included an aluminum skinned WWII fighter plane flying over the Pacific Ocean as well as a woman in a white dress, standing under a blue sky in a field of blossoming flowers. The second part highlighted a Low Rider car club driving their vehicles in and out of a garage, as well as a mechanic doing some welding. All footage was uncompressed and colour graded to Blu-ray’s REC 709 standard and displayed on the aforementioned Dolby PRM 4200. To my eyes, and given the lack of compression, it looked even better than Blu-ray.
Then it was time to watch the footage again, with an enhanced dynamic range, on a modified PRM called the Dolby Experimental Display. This Experimental Display had the exact same 1080p LCD panel as the standard model (same number of pixels, same resolution), but was upgraded to emit a peak luminance of 4,000 Nits (it’s lowest setting was 0.005 Nits).
I watched the enhanced footage by itself as well as side-by-side with the original colour grading. Our eyes tend to be attracted to brighter imagery (thus the reason why big box stores set all their displays to “VIVID”), so I tried my best to make sure appreciable differences were not due to the increased brightness. That said, the enhanced dynamic range was pretty incredible. The same uncompressed footage had been colour graded to something closer to the P3 standard (although Dolby officially announces that it will be capable of up to 2020) and it was stunning all around. More colours, more lifelike details, more everything. To prove that it wasn’t just its own footage, Dolby showed us clips from ‘Samsara’ (shot in 8K resolution), which when given the wider dynamic range, were even more vivid and eye popping than Dolby’s materials. The same goes with the demo using clips from Elysium and The Great Gatsby.
I know from my THX and ISF trainings that colour reproduction is as important as to resolution, the more accurate the colours on display, the more details in the images I could see. I’ve just never experienced colour reproduction this accurate before… even on broadcast monitors! It is quite a revelation.
What Does This Mean For The Rest of Us?
Sure, Dolby turned a few of there super-expensive professional displays into experimental demo displays, and piped in uncompressed video that was professionally colour graded to take advantage of these one-off televisions, but is “High Dynamic Range Imaging” the next 3D or 4K? Another niche, expensive product where I have to replace all my gear? Regardless whether I will ever be able to afford such product is besides the point. I want, however, for this technology to flourish. Ideally in both commercial and home applications.
Dolby thinks their new technology could actually be the thing that helps 4K really take off. But regardless of pixel counts and competing technologies, Dolby wants to create an entire “ecosystem,” or pipeline, that goes directly from content creators to your home cinema without messing up what’s already working.
Starting at the top, today’s colour grading systems (and digital cinema cameras) already work at a much higher quality than what displays are capable of. The problem is that, after the film is made and when it’s time to send it out for Blu-ray or TV broadcast, the limitations are set by a television technology no one uses anymore.
So Dolby is developing a new plugin for colour grading systems that will allow content creators to output their projects in a “container” (think codec) that is fully backwards compatible — it will work with 4K, 1080p, and 720p — but includes “enhancement information” on top of current standards to take advantage of new displays with higher peak luminance levels and wider contrast ratios. Meaning, the content will play on current technology and look pretty good, but will look even better on new gear. This works just like, ironically, DTS HD-Master Audio where the sound data are stored as “core data” and “difference data”. Sony also use the same approach for their “Mastered in 4K” blu-ray releases with Triluminous technology where blacker than black video data and whiter than white video data are tacked on the regular (therefore backwards compatible) core video data.
Another way of putting it: Dolby hopes to enhance the way content is produced and distributed, to free its inherent limitations, without making the consumers change anything. Interestingly, many current gen flat panel displays are capable of 300-400 Nits, with one Sharp model measuring up to 1,000 Nits. Displays are already brighter, but because the content is graded for 100 Nits, if you bump up the brightness (see the aforementioned “Torch Mode”), the colours look like garbage. Therefore, thanks to HDMI, when content in Dolby’s new container hits the streets (or air), some of the current displays *could* see improved contrast and colours (though not all).
That said, if you want the full benefits of Dolby’s innovation, you’ll need a new display from one of Dolby’s impending partners. They’ll likely team with one or more display manufacturers, as well as one or more Hollywood Studios, to announce the “ecosystem” that will take film and/or TV content, put it out on a Blu-ray (or perhaps via a streaming box) to a new UHD (4K) display capable of producing upwards of 10,000 Nits and a 1,000,000:1 native contrast ratio (compared to current generation display, which are colour graded to more like 1,000:1).
Blu-rays already look and sound fantastic, but they can definitely be improved. If we’re already hearing the bit-for-bit identical soundtrack master, Dolby’s VISION could be the closest thing to being on set while the film is in production.