Dolby has played a key role in the development of HDR for both commercial cinema and home theatre applications. From a home entertainment perspective, the company’s most important contribution has been the advanced form of HDR (High Dynamic Range), known as Dolby Vision.
Dolby Vision has the potential to improve consumers’ viewing experience by constantly optimising the way their TVs deliver HDR pictures. It also gives content producers more control over how their HDR programming appears on TVs. And it's coming to smartphones and tablets, too.
Until CES 2017, it was widely assumed that Dolby Vision hardware (screens and Ultra HD Blu-ray players) needed to carry a dedicated chip. However, it is now possible to add Dolby Vision support via a firmware update to devices with sufficiently powerful processors.
The industry standard HDR10 format is free for manufacturers to use, but Dolby Vision requires the payment of a licence fee. So what’s so special about Dolby Vision that hardware brands and consumers would pay extra for it? Quite a bit, actually.
What is Dolby Vision?
The Sony KD-55A1 OLED TV will get a Dolby Vision upgrade soon
The most significant advantage of Dolby Vision HDR versus HDR10 is the addition of dynamic metadata to the core HDR image data.
This metadata carries scene-by-scene instructions that a Dolby Vision-capable display can use to make sure it portrays the content as accurately as possible. Dolby Vision-capable TVs combine the scene-by-scene information received from the source with an awareness of their own capabilities in terms of brightness, contrast and colour performance.
With HDR10 content, your HDR TV only receives static metadata; relatively basic ‘global’ information on the content being shown that applies to the entire film or TV show.
It can’t provide a display with updates on how each specific shot or scene should be shown. Nor does HDR10 carry the same facility for continually optimising the picture to the capabilities of the screen it’s showing on.
Dolby Vision is built on the same core as HDR10, which makes it relatively straightforward for content producers to create HDR10 and Dolby Vision masters together. This means that a Dolby Vision-enabled Ultra HD Blu-ray can also play back in HDR10 on TVs that only support that format.
Dolby Vision allows content producers to have either one or two ‘layers’ of data; one carrying just an HDR signal, the other carrying a standard dynamic range (SDR) signal. This single HDR/SDR workflow approach makes Dolby Vision a convenient tool for content creators and broadcasters to use.
Another advantage of Dolby Vision is that the metadata is embedded into the video signal, meaning it can run across ‘legacy’ HDR connections as far back as version 1.4b. Despite only using static metadata, HDR10 requires HDMI 2.0a compatibility.
On the content production side, Dolby Vision seems more focused on pushing HDR to its technical limits. The minimum specification for Dolby Vision mastering requires the use of reference monitors with a contrast ratio of 200,000:1, peak brightness of 1000 nits, colour range ‘approaching’ the Rec 2020 standard, and support for the SMPTE ST-2084 HDR format.
However, Dolby has also developed a reference ‘Pulsar’ monitor that provides an 800,000:1 contrast ratio, a peak brightness of 4000 nits, and the so-called P3 colour range used in digital cinema applications.
Given its greater creative palette, and the drive towards delivering consumer TVs with ever greater brightness (some of Samsung’s 2018 TVs are claiming to hit over 2000 nits), it’s certainly tempting to see this Dolby Pulsar monitor as a glimpse of HDR to come.
MORE: Sony KD-55A1 review
Will Dolby Vision deliver better pictures?
LG OLED55B7V is a five-star OLED TV with Dolby Vision
Our initial experience of Dolby Vision in the UK was limited to a few Netflix and Amazon streams, plus a handful of Dolby Vision film clips viewed on LG Dolby Vision TVs, and our impressions were that Dolby Vision makes a difference for the better.
In a head-to-head comparison of Dolby Vision and HDR10 demo clips, Dolby Vision images appear to contain more tone definition in bright areas; more balanced, nuanced and natural colours right across the spectrum; better contrast range management; and a greater sense of detail – presumably a side effect of the colour and light management improvements.
However, we've since done a head-to-head comparison using two discs: Despicable Me and Power Rangers in 4K Blu-ray, and the results were unexpected. With Despicable Me, the Dolby Vision effect came across looking rather flat and contrast was more subdued; it was surprisingly less vibrant and spectacular than the HDR10 version of the film.
The Dolby Vision version of Power Rangers, however, is even punchier and more vibrant than the HDR10 alternative, with more nuance thanks to the extra detail that’s revealed in the brightest and darkest areas of the image. It’s not utterly transformative, but it is quite clearly better.
Since Dolby Vision is applied on a disc-by-disc and frame-by-frame basis, it could well be that Despicable Me just isn’t a particularly good example of its implementation, while Power Rangers is more typical of what we should expect from the format.
The small sample size means we can’t draw absolute conclusions on this matter, but what's clear that, when implemented correctly, Dolby Vision can produce marked improvements on an already-impressive HDR10 presentation. We can only take each disc on its own and see how well Vision performs on a case by case basis.
More after the break
How can you watch Dolby Vision?
Our favourite new 4K Blu-ray player, Cambridge CXUHD, supports Dolby Vision HDR
With more and more 4K Blu-ray discs with Dolby Vision hitting the shelves, most 4K Blu-ray players now come with Dolby Vision support as standard. The top end five-star players Cambridge CXUHD and Oppo UDP-203 come with Dolby Vision support (make sure both have the latest firmware update).
Plenty of first-gen 4K disc-spinners – such as the Panasonic DMP-UB900 and Sony UBP-X800 – didn’t support Vision, but that’s been rectified in the 2018 models. Panasonic’s new flagship player DP-UB820 and the new Sony UBP-700 will both be Vision-compatible. LG's UP970 4K Blu-ray player also supports it.
Sony announced that Dolby Vision would be supported on its high-end 2017 TVs (including its A1 OLEDs) as well as being added retrospectively to 2016’s ZD9 LCD TV. The update has finally come through, but it's not the complete solution we've been hoping for. And Sony's new AF8 OLEDs will get Dolby Vision support through a future software update.
The HDR format is also available via the Google Chromecast Ultra, while in the US, Vizio, Hisense, LeEco, Philips (which has a different owner to Philips in Europe) and TCL all already have Dolby Vision TVs on sale or set for launch.
Loewe's first ever 4K OLED TV, Bild 7, will support Dolby Vision
There's the issue of adding to manufacturing costs with the licence fee, and the companies have stated that they trust their own TV processing, and the capability of their own hardware, arguing that it optimises HDR10 images efficiently enough without Dolby Vision. Which, in the Philips 55POS9002's case, seems to have a point.
However, that doesn’t take into account Dolby Vision’s potential for content creators to have more say over how their content appears.
But the main reason Samsung, Panasonic and Philips aren't going to bother with Dolby Vision is because they're instead backing a royalty-free dynamic metadata HDR system called HDR10 Plus (or HDR10+).
Developed by Samsung, and with 20th Century Fox and Warner Bros as partners to license HDR10+ to other manufacturers, it's a direct rival to Dolby Vision. Amazon Prime Video has also signed up to use this technology, with shows such as The Man in the High Castle and The Grand Tour already available for certain Samsung 4K sets in the US. We hope it'll become available for UK sets this year.
We've seen demo clips of HDR10+ at CES 2018, and while it looked mighty impressive against plain ol' HDR10 content, we've yet to see how it compares to Vision.
What Dolby Vision content is available?
Four of the major film studios - Lionsgate, Sony Pictures, Universal and Warner Bros - have promised Dolby Vision UHD Blu-ray releases.
Existing and upcoming titles include mother!, IT, Spider-Man: Homecoming, The Lego Ninjago Movie, Valerian and the City of a Thousand Planets, Power Rangers, Ghost in the Shell and more - see our full list of upcoming 4K Blu-ray releases.
Netflix shows that support Dolby Vision include Marvel's Daredevil, Jessica Jones, Luke Cage and Iron Fist, as well as other Netflix Originals such as Marco Polo, The OA, Santa Clarita Diet, Stranger Things series two and Bright.
Meanwhile, Amazon Video offers Bosch series two and a handful of Sony Pictures films such as After Earth, Fury, Elysium, Men in Black 3 and The Amazon Spider-Man 2 in Dolby Vision, but they're available to US customers only (for now).
More recently, Rakuten has partnered up with Dolby and LG to bring Dolby Vision (and Atmos) movies to its film rental service. Titles include modern blockbusters such as Blade Runner 2049 and Baby Driver and older films such as Bad Boys II and The Amazing Spider-Man.
But with Amazon signed up to offer HDR10+ content as well, does that mean it will eschew Vision in favour of HDR10+, or will it be the only one offering both rival HDR formats? We shall have to wait and see.
The PC game Mass Effect: Andromeda was the first game to support Dolby Vision, heralding a whole new outlet for the format.
Dolby Vision can also be applied in a live broadcast environment – though we’re not aware yet of any broadcaster announcing plans to use it. Besides, another format, Hybrid Log Gamma (HLG), looks set to be the default format used with 4K broadcasts.
What about Dolby Vision on mobile phones and tablets?
Fancy enjoying Dolby Vision videos while on the bus or train to ease your daily commute? There is now a small selection of smartphones that let you do just that.
The LG G6 was the first smartphone to come equipped with Dolby Vision HDR. Since then, it’s been joined by its fellow LG V30 and the new V30S ThinQ, while all three new Apple iPhones – iPhone X, 8 and 8 Plus – support Dolby Vision playback, too.
While other smartphones – such as the Samsung Galaxy Note 8 – support standard HDR for mobile, it’s just the LGs and iPhones that support Dolby Vision content for now.
With Vision content streamed from Netflix (Amazon’s Vision offerings aren’t available in the UK), we found the G6’s LCD display to be sharp and clear, though it will divide opinion - watching a film on a screen with rounded corners takes some getting used to. The V30’s screen was a tad disappointing with HDR content - despite punchy colours, its P-OLED screen didn't show enough definition in the darker scenes, even with brightness cranked to maximum.
Meanwhile, the iPhone X (an OLED display) and iPhone 8 Plus (LCD display) fare much, much better, unearthing excellent shadow detail and textures. The iPhone X, in particular, shines with Dolby Vision shows such as Stranger Things, with colours and detail striking a fine balance between vivid and natural.
What's the future of Dolby Vision?
Dolby has gone out of its way to dismiss talk of any possible format war, positioning its technology as a ‘value added’ proposition in relation to HDR10, not a direct competitor.
Dolby Vision is essentially extra information applied on top of an HDR10 core, so it’s easy to ensure that all Dolby Vision content is also compatible with devices that only support HDR10.
It’s not mandatory for a content creator to deliver both HDR10 and Dolby Vision support though. US streaming platform VUDU did not initially support HDR10 alongside Dolby Vision, nor did Vizio’s first Dolby Vision TVs.
Both have now added HDR10 support, so there is currently no Dolby Vision platform that doesn’t support both. There's no doubt the current HDR landscape is a little rocky, especially when you throw HLG (the broadcast HDR TV format), the LG-only Advanced HDR by Technicolor and, more crucially, Vision's main rival HDR10+ into the equation.
Unfortunately, there's a chance it could only get more confusing as the new formats and standards settle. But fear not - we'll be on hand to help you cut through the jargon.