High dynamic range () is the latest in a long line of "new things you need to know about before you buy a TV." In this article, I'll try to make acquiring that knowledge as painless as possible.
HDR for TVs, best TVs. Sometimes the improvement is subtle, but usually it's there., can deliver the best home video image quality yet. It boosts the brightness of highlights, allows more natural color and can realize the full potential of today's
Unfortunately it comes in three formats, and the two available now, HDR10 and Dolby Vision, sorta compete against one another. They'll soon be joined by. Don't panic! This isn't the kind of format war you may remember from the days of HD-DVD vs. Blu-ray. Your HDR TV will read at least one of these, probably two, and maybe even all three HDR formats.
There are several differences between the different formats, so they're worth discussing in detail.
Winner: Dolby Vision
This is a broad generalization, and in many cases the choice will come down to the specific content and display. But DV can potentially look better for a few reasons. For one thing, it's currently the only HDR format with dynamic metadata. This means that the brightness levels of HDR content can vary between shots, giving filmmakers finer control over how the image looks. HDR10, right now anyway, has static metadata. This means the HDR "look" can only be determined per movie or show.
The other major reason DV could look better than HDR10 is Dolby itself. TV manufacturers must pay Dolby a fee for DV compatibility, but for that fee Dolby will also make sure the TV looks as perfect as possible with Dolby Vision content. It's basically an end-to-end format, with Dolby ensuring all the steps look right, so the result at home looks as good as that content and that display possibly can.
HDR10 is an open format. Each manufacturer is left to their own devices, pun intended. This presumes that the manufacturer will have engineers that know enough about HDR and TVs to get the HDR looking correct on their TVs. This is a big presumption. Most manufacturers' 4K Blu-ray players still have the chroma upsampling error, something that should have been solved in the DVD era (yes, that's a link to an article from 2001 and yes it's amazingly still relevant). So you'd hope that TVs would read the HDR data correctly and look great, but that's not necessarily the case. For example, here are two HDR projectors running the same video. The right one isn't processing the HDR data correctly:
Other factors, such as Dolby Vision being potentially 12-bit over HDR10's 10-bit, is less of a factor given that even the best TVs are now "only" 10-bit. Both formats have too, so that's not a factor.
In CNET's reviews of the new Dolby Vision-equipped, for example, Dolby Vision usually looks better than HDR10. But those advantages could be caused by the TVs' implementation, or how the content is created, rather than the formats themselves. Regardless of the reason, however, it's a fact that on TVs we've compared with Dolby Vision, including LG OLED TVs and LCDs from Vizio and TCL, that format tends to outperform HDR10.
Hybrid log gamma, the third HDR format, doesn't have the capability to be as, for lack of a better word, dynamic as DV and HDR10. However, it's still HDR, still better than SDR, and has a big advantage we'll discuss farther down.
Because there are no licensing fees, far more companies have HDR10 support than Dolby Vision. Or to put it another way, if it's HDR, it supports HDR10. Some HDR gear also supports Dolby Vision. As mentioned above, implementing DV is more than just settings or a badge on the side. Dolby is involved before the product is shipped to help ensure it all works as they specify.
HLG, not yet widely available, isn't really part of this race. Also, it's likely most HDR TVs can add HLG support via firmware, though that's not a given.
Winner: HDR10… for now
This is likely to change, or at least become a closer contest. Now that iTunes supports HDR, and specifically Dolby Vision, it's likely we'll begin to see a lot more Dolby Vision content. It's also supported on Amazon, Netflix and VUDU, though of course not all HDR shows will be DV.
The same is true with 4K Blu-ray. There are a growing number of titles and almost them are HDR10. A subsection of those also have Dolby Vision, but there are no DV-only 4KBD titles.
Winner, by default: HLG
is the only HDR format that's backwards compatible with standard dynamic range TVs. An HLG signal can be read by SDR TVs and shown normally, and it can also be read by HLG-compatible TVs and shown as HDR. This is its contribution to the HDR world. It's primarily intended for broadcast TV, which isn't surprising when you consider it was co-developed by the BBC and Japan's NHK.
Being a hybrid, it doesn't quite have the range you can achieve with DV and HDR10, but that's not really the point. The idea is to offer HDR where it was impossible to offer with the other formats. So the real competition, if you can call it that, is with standard dynamic range. And in that fight it handily wins.
No winner (or loser) yet
Though it'd be easy to call this a format war, I'm hesitant to do so. There's not hard line with HDR, as there was with Blu-ray and HD-DVD, VHS and Beta or PlayStation and Xbox. In previous "wars" you had to choose, and if you chose wrong, your gear wouldn't work. Even if you chose right, you'd still be left with a catalog of titles from the other format you couldn't watch.
There isn't that with HDR10, Dolby Vision and HLG. Every HDR device can play HDR10. Some can also play Dolby Vision. In theory, Dolby Vision offers a slight step up in picture quality. So in that case, it's more like a "premium" offering. If your TV doesn't support DV, you'll still be able to watch all that content in HDR10. Maybe there will be a time when that's an obvious step down, but right now any HDR is better than SDR, so it's not a huge deal.
And then there's HLG. Right now it's a non-issue, but you'll be seeing a lot more of it in future. There's a good chance your current HDR TV plays, or will be upgraded to play, HLG content. That content will again be separate from HDR10 and DV.
Now and the future
On the horizon is yet another option:. It will have dynamic metadata like Dolby Vision, potentially narrowing the gap between the formats. However, currently only Samsung, Panasonic, Amazon and Fox have signed on to this new, but open and royalty free, format. It's possible that current TVs could be updated, via firmware, to play HDR10+, but that remains to be seen.
In the meantime, there's more and more HDR content, and a lot of it looks great. Like in the early days of HD and 4K, there will be some growing pains to get most content looking decent.
If you're shopping for a TV now, should a specific type of HDR compatibility be considered? Not really. It's far more important that the TV actually performs well with all types of content, and that it. You can consider Dolby Vision a bonus.
Got a question for Geoff? First, check out all the other articles he's written on topics like why all HDMI cables are the same, TV resolutions explained, LED LCD vs. OLED and more. Still have a question? Tweet at him @TechWriterGeoff then check out his travel photography on Instagram. He also thinks you should check out his best-selling sci-fi novel and its sequel.