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What is HDR for TV and why should it interest you?


Geoffrey Morrison

HDR (High Dynamic Range) is the next big topic in televisions.

We have talked about it for several years . However, HDR-compatible TVs are much more common. Almost all 201

7 mid-range and high-end televisions have HDR, and HDR content is becoming more prevalent in streaming services such as Netflix and Ultra HD Blu-ray Discs .

Is this new technology worth it? Hype? In two words: largely yes. I'm pretty baffled when it comes to new TV technologies, and I'm really excited about HDR. And I'm not the only one.

What is a high dynamic range?

The two most important factors for the appearance of a TV are the contrast ratio or the brightness and darkness of the TV, and Color Accuracy . Basically, this is how much colors on the screen look like real life (or whatever the director is going to do). This is not only my opinion, but also that of almost all other TV reviewers, people who have participated in multi-TV face-offs in stores and for websites / magazines, and industry experts like the Imaging Science Foundation and Joe Kane.

If you place two TVs next to each other, one with a better contrast ratio and a more accurate color, and the other with a higher resolution (more pixels), the TV with a higher contrast ratio will be chosen by just about any viewer. It looks more natural, "pops" more and just looks more "real", though it has a lower resolution. In other words, a 1080p resolution TV with excellent contrast and excellent color will always beat a 4K resolution TV with average contrast and average color.

HDR significantly expands the contrast and color range. Bright parts of the picture can become much brighter, so the picture seems to have more "depth". The colors are expanded to show brighter blues, greens, reds, and everything in between.

A wide color gamut (WCG) is provided for driving with HDR, and this brings even more colors to the table. Colors that were previously not reproducible on any TV. The reds of a fire truck, the deep violet of an eggplant, even the green of many street signs. You may never have noticed that this was not exactly what it looked like in real life, but you will know it now. WCG puts these and more millions of colors in your eyes.

For a set of background information on how to work with colors on TVs, see Ultra HD 4K TV Color, Part I: Red, Green, Blue and Beyond, and Ultra HD 4K TV Color, Part II: The (near ) Future.

Photo HDR is not TV-HDR

One of the most important things you should know about HDR TVs is that TV-HDR is not the same as Photo HDR . Every article I wrote about HDR contains comments from people complaining about the hyperrealistic look common in HDR photography. These are two very different things that unfortunately and confusingly have the same name. Like football and soccer.

I wrote a full article on the difference but the most important finding is that HDR is not a ghosting gimmick for televisions (similar to the soap opera effect ). It is definitely not that.

TV HDR : Extending the contrast ratio and color gamut of the TV to provide a more realistic, natural image than is possible with today's HDTVs is.

Photo HDR : Combining multiple images with different exposures to create a single image that mimics a wider dynamic range.

Photo HDR: Take two or more pictures (left and center) and combine them to cover some aspects of to show both (right).
Geoffrey Morrison

HDR for TV is designed to give you a more realistic picture with more contrast, brightness and color than before.

An HDR photo is not a "high dynamic range" in this sense. The image does not have the dynamic range that is possible with real HDR. It is still a default image with dynamic range, it only contains some additional information due to the additional exposures.

A TV HDR image does not look any different than a photo HDR image. It only looks better .

I hate to explain this point, but due to the two processes with the same name, this understanding is the biggest hurdle for HDR faces. If you're open minded, you should look around for HDR to find out what it is and be blown away by a demo – and the demos are incredible. These confident HDRs are not worth their time, will never bother to see the demo, and will poison the fountain (so to speak).

How does it work?

There are two parts of the HDR system: the TV and the source.

The first part, the TV, is actually the simpler part. In order to be HDR compatible, the television should be able to produce more light than a standard TV in certain image areas. This is basically just like local dimming but in an even larger area.

HDR has a broad color space or WCG linked to it. For years, TVs have been able to offer a wider color palette than Blu-ray or HD downloads / streaming. The problem is that you do not really want the TV to produce these colors at will. It's best if the director decides what the color of his movie or television show should look like, rather than a TV whose color expansion process was designed in a few days, 6,000 miles from Hollywood. More information soon.

Of course, it costs money to make TVs brighter and more colorful, and some HDR TVs deliver better picture quality than others. Just because a TV is HDR-compatible does not mean it will outperform non-HDR televisions. The only thing the HDR label really means is that the TV can play HDR movies and TV shows, not as good.

The content is the hard part. To look really good, the HDR TV needs HDR content. Fortunately, the amount of HDR content is growing fast. The main 4K streaming services like Netflix and Amazon both have HDR content. Like many others too.

Another source of HDR is physical media. Ultra HD Blu-ray is the latest physical disc format. You need a new UHDBD player to play these discs, but your current Blu-ray and DVDs can be played on the new players. Not all UHDBD discs have HDR, but many do.

HDR content (the key)

When creating a movie or television program, the director and cameraman work with a colorist to give the program the right look. Winterfell's subdued, cold shades in "Game of Thrones" face the richness and warmth of King's Landing. If you lived in a cave without HBO or Internet, I mean the following:


When creating movies, the team can use the wide range of Digital Cinema P3 color space to create beautiful teals, oranges and violets.

But then it's time to get these movies up and running on TV. To accomplish this, this team essentially "dumbs" the image by removing the dynamic range and restricting the color. Given the limitations of the HDTV system, they look the way they want, and this limited version is available on Blu-ray or as a download.

If your TV is set to movie or movie mode, this is the case is about what you get at home. If you are in "Lively" or "Dynamic" mode, the colors will be exaggerated by the TV as you like . Something is created that is not there, because in the mastering phase, the director and her team had to get this all out. Is the "Vivid" version close to what they saw or what was in the theater? This is doubtful, and there is no way to know it, since it is the creation of your TV.

Adding additional data, called metadata, to the signal can be added to the signal with the added storage and transmission capabilities of 4K BD and the streaming of videos from Amazon, Netflix, and others. He tells HDR / WCG TVs exactly what they should look like, which deeper colors to display, and how bright a particular highlight, reflection, star, sun, explosion, or whatever should be. It can even adjust the picture settings or automatically set the TV to a specific picture mode. This is a huge improvement in the appearance of images on televisions.

Technicolor's Smart Tint Mapping is a content creator tool that makes it easy to create HDR content (such as more cost-effective). I saw it in action and the results are very promising . This is a good thing, since it is not labor intensive to create HDR versions of movies and shows. If it would take a lot of time and time equals money, we would never get HDR content. This is just one example of this process.

What about cables and connectors?

HDR probably will not need new cables. Current high-speed HDMI cables can carry HDR. The source device (such as a 4K Blu-ray player) and the TV must have at least HDMI 2.0a to transfer the metadata. If you have a receiver and want to use it for switching, must also be HDMI 2.0a .

If you've bought a receiver or media stream in recent years, it's best to check with the manufacturer if your TV is HDR and you want to try it out. If your TV is HDR, the internal streaming apps should also support HDR so that you can go that way as well.


Most of the experts I've talked to, both in terms of content page and the TV page are excited about HDR and WCG. 4K itself had no one in those camps that was so excited. The usual refrain was: "More pixels are cool, but better pixels would be amazing."

Although 4K was breathlessly referred to as the next-generation TV evolution, it was anything but. With HDR and WCG we look at the promised evolution and it should be brighter and more colorful.

Do you have a question for Geoff? First, look at all the other articles he said on issues like why all HDMI cables are the same, explained TV resolutions, LED LCD. OLED and more. Do you have another question? Tweet Him @TechWriterGeoff then check out his travel photography on Instagram. He also thinks you should look at his best-selling science fiction novel and its sequel.

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