What is HDR?

Go beyond 4K with high-dynamic range - 2017's top TV tech

If last year saw 4K finally take off, then in 2017 it's very much the turn of HDR.

As was the case with 100Hz, high definition and 3D before it, HDR is a new bit of TV technology designed to make you want to spend hundreds of pounds on a new telly. And the best part is that it's genuinely amazing and you don’t even have to don a ridiculous pair of glasses to see it.

From the PlayStation 4 Pro to Netflix, there are loads of platforms that already support HDR and even more are on the way. Pretty much all the of the new 4K TVs launched at CES 2017 feature HDR smarts, which means the tech's going to be pretty widespread before you know it.

Here’s our guide to what HDR is and why you should be very excited about it.

What does HDR stand for?

As keen photographers amongst you will know, HDR is short for High Dynamic Range.

Essentially, it refers to an image that displays far greater contrast - so dark areas of the picture look darker while, at the same time, bright areas look brighter.

An image's dynamic range is the contrast between its brightest whites and darkest blacks, and HDR images boast much greater constrast than regular images.

Increasing contrast actually also has huge knock-on effects to other areas of a picture. It enhances the detail you can see in darker areas, for example.

The sample pictures above, provided by Sony, illustrate the difference between standard and high dynamic range pictures.

And now HDR isn’t confined to still images: it’s on your TV and the cinema screen.

What’s so great about it?

With the extra luminance, images become vastly more true to life.

Dark scenes become less of a gloom-fest – you’ll be able to pick out far more in the shadows – while the added vigour of bright areas helps them to leap out of the screen. Colours also become more realistic - way, way more punchier when they need to be, but also more subtle and expressive, with more delicate blends and shifts in tone.

As mentioned above, you get more insight into dark areas, and the enhanced contrast also serves to highlight textures and objects right across the image, which can have a pretty transformative effect on perceived detail and sharpness.

Basically, it makes things look more realistic, more dramatic and more nuanced.

But what about 4K? Doesn’t that add more detail too?

Yes, but it’s a different kind of detail. HDR isn’t about increasing the number of pixels, but about making every pixel that’s already there better. And this means that, while 4K generally requires a large screen size to prove effective, HDR’s advantages are plainly visible on a screen of any size.

But don't worry, it's extremely unlikely you'll ever be given the option to buy an HDR TV that doesn't also support 4K, because it's generally seen as a layer of technology above Ultra HD. Of course, there are lots of TVs currently available that will handle 4K and not HDR, but those will become less common as 2017 progresses. In short, if you buy a TV in 2017 it shouldn't be too difficult to get one that utilises both technologies to deliver stunning all-round image quality.

Within Hollywood, some TV and filmmakers believe that HDR could be a bigger deal than 4K. Howard Lukk, VP of production technology for Walt Disney Studios, told Variety: “There’s a feeling in Hollywood, and even at the Walt Disney Studios, in order to change over the complete marketplace to a new format, we really need more than just pixels. Adding more dynamic range and more contrast really makes a big difference”.

Are there any bad sides to HDR?

Well, HDR video requires more data than standard dynamic range video, and as we stream more and more that can have an impact on broadband charges. It could even be simply unavailable to those people without fast enough download speeds, although Netflix and the like are already doing an excellent job of optimising streams to make them as bandwidth-light as possible.

And anyone who has spent time browsing HDR photos on Flickr will know that the effect can often be overused, creating an image that trades subtlety for tasteless impact (there's even an entire subreddit dedicated to these eye-polluting abominations). There’s a danger that this lack of restraint could also afflict HDR video - but given that mastering will be mostly in the hands of highly experienced professionals, we're not too concerned about that.

The only other thing to bear in mind is that just because two TVs both support HDR doesn't mean they both have the same contrast levels or dynamic range, as the HDR standards set out minimum requirements that manufacturers can exceed for even better results.

Did you notice that we said "HDR standards" rather than "HDR standard"? Yep, there's more than one in play here...

Multiple HDR standards? Is this where Dolby Vision comes in?

Don't worry; this honestly isn't as confusing or annoying as it might initially seem.

By far the most common HDR standard out there right now is called HDR10 - it's what the PS4, PS4 Pro and Xbox One S support, and its built into the TVs from all of the major manufacturers. In fact, it forms part of the Ultra HD Premium spec, so if you buy a TV or other device with the logo above printed on the box, it supports HDR10.

HDR10 is a massive step-up from standard dynamic range, but it's not actually the ultimate HDR format. For that you need to look towards Dolby Vision, which requires even brighter outputs and wider colour gamuts than HDR10. It also requires a patented Dolby chip and a small licensing fee so is currently far less common. Having said that, it does seem that LG's OLEDs and Sony's A1 OLED, which are practically the only TVs to support it so far, are really just the start.

Besides, if you do buy a Dolby Vision TV it will almost certainly support HDR10 as well, so it's worth considering for future proofing reasons - and Netflix and Amazon both stream in Dolby Vision (as well as HDR10) already.

What about other HDR formats? Well, Hybrid-Log Gamma is a standard HDR format developed by the BBC and Japan’s NHK for broadcasting live TV, but it’ll still be a good few years before you can watch the World Cup in high dynamic range. And Advanced HDR is a similar deal with a focus on upscaling SDR content into HDR.

In short, you don't really need to worry about those last two formats. Just focus on HDR10 and Dolby Vision, the first of which will be pretty ubiquitous through 2017, the latter of which offers a step-up reserved for only the most luxurious of tellies for the time being but could well become far more common in 2018 and beyond.

How do I watch HDR?

You’ll need a compatible TV to watch HDR content. So far almost all the TVs released or announced that offer HDR compatibility are also 4K, and there are a fair few of them about right now.

All of Samsung’s 2016 SUHD 4K range was HDR compatible, and the same goes for its new QLED TVs that were announced at this year’s CES. Those sets are due out in March, but if you want to pick up an affordable HDR tele right now then the Samsung UE55KS7000 is a fantastic option.

The same broad embrace of HDR applies to LG, whose 2016 and 2017 OLEDs are fully onboard with the format. In fact, the LG OLED55C6V is currently sitting pretty at the summit of our Top 10 TVs. It costs £1,800 though, so isn’t especially cheap. Mind you, neither is its new, ultra-thin Signature 77W7.

Elsewhere, Sony and Panasonic’s latest OLEDs support HDR, as do their LCD models for 2017. Oh, and Hisense’s ridiculous Laser TV will project a 4K HDR picture onto a 100-inch screen for the pricely cost of $13,000.

But while these super high-end models will be real showcases for HDR, what's perhaps more exciting is that 2017 will be the year that HDR TVs become genuinely affordable. We actually saw a 43in Samsung HDR telly dip down to £350 during Black Friday 2016. This year expect that sort of thing to be more norm than exception.

What can I watch in HDR?

In short: loads of stuff. Plenty of Netflix and Amazon Instant Video originals can be streamed in 4K and HDR. That means the likes of Daredevil, Man In The High Castle, Marco Polo and Transparent all support the format, and you can expect that catalogue to expand further this year. Beyond those in-house titles, it’s slim pickings for streamed HDR content because most TV networks don’t film in the format or broadcast in 4K. YouTube also supports HDR as well, but the uploads are hit and miss.

And if you want to watch 4K HDR movies? You’re best off sticking to 4K Blu-rays at the moment. We saw a number of 4K Blu-ray players released last year, the best of which was Panasonic’s five-star DMP-UB900, but only the Xbox One S was an affordable way to watch flicks such as The Revenant, Deadpool and Suicide Squad.

Speaking of the Xbox One S, gaming is currently one of the best ways to experience HDR content. Not only do Forza Horizon 3 and Gears of War 4 look stunning on Micorsoft’s latest console, but every PlayStation 4 supports the format as well. That means any game patched for the format - Uncharted 4 and The Last of Us Remastered are our favourite picks so far - will show off an added visual gloss.