The latest? HDR. But what is it and why will it make your video pictures look better than ever? Read on for all you need to know about HDR video technology on 4K TVs, games consoles, mobile phones and more...
What does HDR mean?
‘HDR’ stands for High Dynamic Range, and it is the next big thing in the video world, primarily when it comes to 4K TVs and 4K content. The term originates in photography, and refers to a technique that heightens a picture’s dynamic range – the contrast between the brightest whites and the darkest blacks.
The theory is that the higher the dynamic range, the closer a picture gets to real life. HDR for televisions is basically the same idea.
Look out of the window. Look at the sky. The clouds may be white (or grey, if you’re in the UK) but there should be definite layers, and around the clouds you should be able to pick out varying degrees of brightness.
Now look at clouds in any film on your TV. They tend to look flat in comparison, with white levels crushed and layers that are virtually indistinguishable. There are several reasons for this.
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What's so good about HDR?
The first reason is your TV’s limited dynamic range, its inability to illustrate the finest differences in brightness. That means you miss out on all the nuances that really ought to be there.
After all, your eyes can differentiate a lot more information than your telly feeds you. Then there’s all the processing that takes place along the chain after something is filmed.
It dramatically reduces the amount of information transferred in order to match the technical limits imposed by your TV.
Only now, TVs are much more capable. And by that, we mean bright. A normal TV puts out around 100-300nits of brightness, where one nit (derived from the Latin for ‘to shine’) is equivalent to the light provided by one candle. An HDR TV can in theory get up to 5000nits.
Of course, that sort of light would be blinding at maximum brightness. This tech isn’t about searing your retinas, though - it’s about widening the range in order to display finer increments of shading.
The idea is to let you see more of what is recorded. You’ll get more details in the shadows and highlights. Sunlight will gleam properly off windows. Colours will be richer and more lifelike, with more delicate gradations and greater shifts in tone. Basically, your picture will look more natural and more real.
Don't believe us? Take it from Hollywood colourist, Dado Valentic, in our video below...
What is HDR10?
Currently, there are five different varieties of HDR: HDR10, HDR10Plus, HLG, Dolby Vision, and Advanced HDR by Technicolor.
HDR10 is the original and currently most common form of HDR. It's an open standard that has been adopted by numerous manufacturers, service providers (Amazon and Netflix) and the Blu-ray Disc Association (BDA).
According to the CEA (Consumer Electronics Association), HDR10 should meet certain standards, including 4:2:0 colour sub-sampling, 10-bit bit depth, and the BT.2020 colour space.
What is Dolby Vision?
As previously mentioned, Dolby has its own version of HDR: Dolby Vision. This was initially an initiative for its Dolby Cinemas, to combine HDR video with Dolby Atmos sound, in an attempt to take on IMAX cinemas, but Dolby Vision can also be adapted for the home.
The key difference between Dolby Vision and HDR10 (besides the fact Dolby Vision requires payment of a licence fee) is that the former allows for dynamic metadata to be added to a vanilla HDR image. In theory, this allows for an improved image on a scene-by-scene basis - while HDR 10 works its magic film-by-film.
Both HDR10 and Dolby Vision can, and will, appear on the same TVs and discs - the two can happily coexist (Amazon Prime Video and Netflix offer both), although you will need a Dolby Vision-compatible Blu-ray, Blu-ray player and TV all capable of processing it before you can enjoy the technology at home.
More after the break
What is HDR10 Plus?
To confuse matters, Samsung has also developed its own standard of HDR called HDR10 Plus.
Just like Dolby Vision HDR, Samsung's tech uses dynamic metadata in compatible content to boost HDR images scene-by-scene and even frame-by-frame.
Samsung doesn’t support Dolby Vision on any of its TVs, and it’s not a stretch to say its system is a direct rival to Dolby’s.
Amazon Video is the first content provider to announce support for HDR10+ and is aiming to deliver compatible shows in 4K HDR10+ globally, by the end of 2017.
All of Samsung’s 2017 4K TVs will have HDR10+ support built-in, while a firmware update will make it available to existing 2016 4K TVs later in the year.
What is HLG?
HLG (Hybrid Log Gamma) is potentially the most important HDR format of all. Why? Because it's going to be used with TV broadcasts.
It's the result of a joint research project between the BBC in the UK and NHK in Japan.
It's designed to deliver a more convenient HDR solution for the broadcast world than HDR10. It takes standard dynamic range and high dynamic range images and combines them into one feed, with HLG-compatible 4K TVs able to decode and show the HDR images in all their glory.
Most big-name manufacturers have confirmed their 2017 sets will be HLG ready, with Samsung and LG also confirming that their 2016 HDR TVs will receive HLG support via firmware update. We're yet to get confirmation of that from Panasonic or Sony.
What is Advanced HDR by Technicolor?
Advanced HDR by Technicolor is a new format of HDR launched at CES 2017. It's the result of a collaboration between LG and Technicolor, the video specialists.
As with the other types of HDR, the content needs to be mastered in the format, played back by a source that can read the Advanced HDR data and then displayed by a compatible television or projector.
There's no official word on any upcoming content that's been mastered in Advanced HDR by Technicolor, although a number of LG's 2017 TVs (both 4K OLED and LCD) are compatible with the format.
HDR and 4K Ultra HD
LG's 65EF950V OLED TV is fully compatible with HDR content
HDR should not be confused with the other big TV buzzword of the moment: UHD (Ultra High Definition), also known as 4K. Both HDR and UHD are meant to improve your viewing experience, but they are hugely different technologies with almost no overlap.
It’s a matter of quantity and quality. UHD is all about bumping up the pixel count, while HDR wants to make the pixels you have more accurate, regardless of resolution. Whether you’ve got a 32in unit in the bedroom or a 75in monster in the living room, HDR could make a visible difference.
Of course, while UHD and HDR are different technologies, they can still work together. The vast majority of HDR-compatible TVs on the market are also 4K Ultra HD TVs, although Sony does have a 2017 range of Full HD TVs that also supports HDR.
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How can you watch HDR?
To benefit from HDR10 or Dolby Vision, you’re going to need a few things. First stop is your display. Whether you’re after a television, a projector, a mobile phone or tablet, it needs to be HDR-compatible.
LG, Samsung, Sony and Panasonic all have their own HDR TVs - chances are your next 4K TV will support the format. Some of the best HDR TVs we've reviewed include the Samsung UE49KS8000, LG OLED55B7V, and Sony KD-55A1.
This is a small point, but don't confuse normal HDR with picture processing modes such as HDR+ or HDR Effect. These are modes (used by Samsung and LG respectively) that claim to create HDR-quality images from non-HDR content.
The next step is to get something to play it on. If your HDR content happens to be on a disc, i.e. an Ultra HD Blu-ray, you're going to need an Ultra HD Blu-ray player to play it on. Our current favourites are the Panasonic DMP-UB900, Sony UBP-X800 and Oppo UDP-203, but Microsoft's Xbox One S and the newly-announced Xbox One X also play 4K Blu-rays and include HDR10 support. Sony's PlayStation Slim and PlayStation Pro aren't 4K players but they are compatible with HDR10 content, including games.
Alternatively, perhaps you're streaming HDR content via Netflix or Amazon Prime Video. This can be done through a compatible app on your TV or streaming box such as the latest Amazon Fire TV. For that, you’ll also need an internet connection with the appropriate bandwidth. Both services support HDR10 and Dolby Vision.
HDR on the Xbox One S, One X and PS4 Pro
The Xbox One S not only has an Ultra HD Blu-ray player, it also supports HDR video. You'll need a TV that supports HDR10 to view HDR content from the Xbox One S.
Provided HDR is supported on your TV (and turned on), then both consoles can output HDR video from any compatible source - Ultra HD Blu-ray discs, HDR streaming services and HDR games.
The first Xbox One S HDR games are already here - titles that support it include Battlefield 1, NBA 2K17, Forza Horizon 3 and Gears of War 4.
While the new PS4 Pro launched without a 4K Blu-ray drive, it does support games that have been optimised for HDR such as Uncharted 4: A Thief's End and Deus Ex Mankind Divided.
What about mobile HDR?
The ill-fated Samsung Galaxy Note 7 was the first HDR smartphone. Since then, we've seen the LG G6 and Sony Xperia XZ Premium launch with HDR - the former packs in HDR10 and Dolby Vision support, while the latter is the world's first 4K HDR phone.
The UHD Alliance - the organisation that sets standards for Ultra High Definition content - has also set the minimum spec for 4K phones and other portable devices showing HDR content.
Called Mobile HDR Premium, the standard is essentially a certification for smartphones, tablets and laptops that meet minimum standards in terms of resolution, dynamic range, colour space and bit depth i.e. you're guaranteed a certain level of experience when watching 4K HDR content. The label will also be applicable to 4K HDR content optimised for mobile devices.
What HDR content is available?
HDR content is filmed or mastered in HDR – playing ordinary footage on an HDR TV alone won’t cut it. Amazon Prime Video was the first service to stream ‘HDR’ footage, but Netflix also has its fair share of HDR content including Chef's Table, Marco Polo, Marvel's Daredevil, and Marvel's Jessica Jones.
Amazon Video also offers mobile HDR videos for streaming on HDR-compatible phones, such as the ill-fated Samsung Galaxy Note 7. Mobile HDR content includes Amazon Original Series and other "top titles".
The future of HDR
There's no denying HDR is a very attractive idea - and when we've seen it in action the results, on the whole, have been highly impressive.
The combination of 4K and HDR on a TV means a super-sharp, super-dynamic picture – and from our experience it's a clear step-up from the HD that most of us have come to know and love.
HDR content will continue to hit the mainstream via streaming services and Ultra HD Blu-ray, which combines Ultra HD with HDR on one disc. For many enthusiasts, this could be the complete AV package.
2017 looks set to be the year that HDR becomes a reality for more consumers and it's something that should be considered when upgrading your current TV. The only potential fly in the ointment is the different flavours of HDR and making sure your TV is future-proofed for when/if the different variants go mainstream.
As long as consumers have access to the displays, the sources and the content to complete the HDR chain, the future of video looks very bright...
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