![https://cnet4.cbsistatic.com/img/aQ_7xrC2zWXHv4vDE9YeHuNtbKw=/970x0/2015/09/17/e77cf429-7282-4380-b934-2d67492da47a/photo-hdr-example.jpg"](https://cnet4.cbsistatic.com/img/aQ_7xrC2zWXHv4vDE9YeHuNtbKw=/970x0/2015/09/17/e77cf429-7282-4380-b934-2d67492da47a/photo-hdr-example.jpg"){kind=link}
![https://cnet4.cbsistatic.com/img/yQzvUf9mJgs7WTpceR_21-d2Kf4=/970x0/2015/09/17/6dac9303-4006-47ac-85c9-25e55d170137/game-of-thrones-cool-and-warm.jpg"](https://cnet4.cbsistatic.com/img/yQzvUf9mJgs7WTpceR_21-d2Kf4=/970x0/2015/09/17/6dac9303-4006-47ac-85c9-25e55d170137/game-of-thrones-cool-and-warm.jpg"){kind=link}
A good overview of HDR/WCG with a discussion about multi-exposure HDR as well.
I've added a few comments in-line for emphasis.
Regards
Craig
https://www.cnet.com/news/what-is-hdr-for-tvs-and-why-should-you-care/
What is HDR for TVs, and why should you care?
High dynamic range (HDR) TVs are here and so is the first HDR content, with
more of both on the way. Is this next-gen TV technology worth getting in your
next TV?
TVs September 21, 2015 1:00 AM PDT
HDR, or high dynamic range, is poised to be the next big thing in TVs.
We've been talking about it for several years, but finally a few HDR-compatible
TVs are on the market, the first HDR TV shows and movies are available to
stream, and later this year or in early 2016, Ultra HD Blu-ray discs will
likely appear with HDR titles, not to mention the new players to play them.
Is this new technology worth the hype? In two words: yes, hopefully. I am
pretty jaded when it comes to new TV tech, and I'm really excited about HDR.
And I'm not the only one.
What is high dynamic range?
The two most important factors in how a TV looks are contrast ratio, or how
bright and dark the TV can get, and color accuracy, which is basically how
closely colors on the screen resemble real life (or whatever palette the
director intends). This isn't just from my years of TV testing, but in pretty
much every multiviewer TV test and the years of testing from industry experts
like the Imaging Science Foundation and Joe Kane.
***** This is the crux of the discussion*****
If you put two TVs side by side, and one has a better contrast ratio and more
accurate color, and the other just has higher resolution (more pixels), the one
with greater contrast ratio will be picked by pretty much every viewer. It will
look more natural, "pop" more, and just seem more "real," despite having lower
resolution. In other words, a 1080p resolution TV with excellent contrast and
color beats a 4K resolution TV with average contrast and color every time.
*****As I told Bert, HDR and WCG provide "the Sparkle."*****
HDR expands the range of both contrast and color significantly. Bright parts of
the image can get much brighter, so the image seems to have more "depth."
Colors get expanded to show more bright blues, greens, reds and everything in
between.
Wide color gamut (WCG) is coming along for the ride with HDR, and that brings
even more colors to the table, colors so far impossible to reproduce with TVs
up to this point. The reds of a stop sign or fire truck, the deep violet of an
eggplant, even the green of many street signs. You may have never noticed
before that these weren't exactly how they looked in real life, but you sure
will now. WCG will bring these colors and millions more to your eyeballs.
Photo HDR isn't TV HDR
One of the most important things to know about HDR TVs is that TV HDR is not
the same as photo HDR. Every article I've written about HDR has comments from
people complaining about the hyper-realistic look common with HDR photography.
These are two very different things that, unfortunately and confusingly, just
happen to share the same name. Like football and football.
I wrote an entire article about the difference, but the main takeaway is that
HDR for TVs is not a picture-degrading gimmick (akin to the soap opera effect).
It is definitely not that.
TV HDR: Expanding the TV's contrast ratio and color palette to offer a more
realistic, natural image than what's possible with today's HDTVs.
Photo HDR: Combining multiple images with different exposures to create a
single image that mimics a greater dynamic range.
<span itemprop="image" itemscope itemtype="https://schema.org/ImageObject";><img
src="https://cnet4.cbsistatic.com/img/aQ_7xrC2zWXHv4vDE9YeHuNtbKw=/970x0/2015/09/17/e77cf429-7282-4380-b934-2d67492da47a/photo-hdr-example.jpg";
class="" alt="photo-hdr-example.jpg" height="0" width="970"><meta
itemprop="url"
content="https://cnet4.cbsistatic.com/img/aQ_7xrC2zWXHv4vDE9YeHuNtbKw=/970x0/2015/09/17/e77cf429-7282-4380-b934-2d67492da47a/photo-hdr-example.jpg";><meta
itemprop="height" content="0"><meta itemprop="width" content="970"></span>
Photo HDR: Taking two or more images (left and center) and combining them to
show some aspects of both (right). Geoffrey Morrison
HDR for TVs aims to show you a more realistic image, one with more contrast,
brightness and color than before.
An HDR photo isn't "high dynamic range" in this sense. The image doesn't have
the dynamic range possible in true HDR. It's still a standard dynamic
rangeimage, it just has some additional info in it due to the additional
exposures.
*****I disagree slightly with the author here. Using three exposures DOES
capture extended HDR information; otherwise it would not be possible to create
an improved 8 bit image. But creating a new (improved) 8 bit image does not
increase the dynamic range on an 8 bit display. But it is quite easy to take
the three exposures and create a 10 bit image with improved dynamic range. No
doubt this will happen.*****
A TV HDR image won't look different the way a photo HDR image does. It merely
looks better.
*****Yup! Because it can deliver improved dynamic range.*****
I hate to belabor the point, but due to the two processes sharing the same
name, this understanding is really the first, biggest hurdle HDR faces. Those
with an open mind might seek out HDR to find out what it is, and be blown away
by a demo -- and the demos are amazing. Those convinced HDR isn't worth their
time, won't ever bother to see the demo and will poison the well (so to speak).
Remember the "wow" you experienced the first time you saw HDTV? HDR is that.
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 easier part. To be HDR-compatible, the
TV should be able to produce more light than a normal TV in certain areas of
the image. This is basically just like local dimming, but to an even greater
range.
Tied in with HDR is wide color gamut, or WCG. For years, TVs have been capable
of a greater range of colors than what's possible in Blu-ray or HD downloads.
The problem is, you don't really want the TV just creating those colors
willy-nilly. It's best left to the director to decide how they wants the colors
of their movie or TV show to look, not a TV whose color expanding process might
have been designed in a few days 6,000 miles from Hollywood. More on this in a
moment.
Of course, making TVs brighter and more colorful costs money, and some HDR TVs
will deliver better picture quality than others. Just because a TV is
HDR-compatible doesn't necessarily mean it's going to outperform non-HDR TVs.
The only thing the HDR label really means is that the TV will be able to
display HDR movies and TV shows.
The content is the hard part. To truly look good, the HDR TV needs HDR content,
which today is almost nonexistent. TV shows and movies with 4K resolution are
rare enough, but HDR TV shows and movies are even rarer. Only Amazon has
released any so far, and it consists of just a couple of shows and a handful of
Sony films. Netflix has said it will offer HDR before the end of 2015, but no
other content provider has yet announced HDR for the home.
Another source of HDR will be physical discs. The Ultra HD specification allows
the discs to carry HDR versions, with Dolby Vision as an option. The trick is,
how many 4KBD titles will we see with HDR, especially at the beginning? One
hint to that is how easy (read: cheap) is it to create an HDR version of a
movie. Turns out, we have some clues to that.
HDR content (the key)
When a movie or TV show is created, the director and cinematographer work with
a colorist to give the program the right look. Take the muted, cold color tones
of Winterfell in "Game of Thrones" versus the richness and warmth in King's
Landing. If you've been living in a cave without HBO or the Internet, here's
what I mean:
<span itemprop="image" itemscope itemtype="https://schema.org/ImageObject";><img
src="https://cnet4.cbsistatic.com/img/yQzvUf9mJgs7WTpceR_21-d2Kf4=/970x0/2015/09/17/6dac9303-4006-47ac-85c9-25e55d170137/game-of-thrones-cool-and-warm.jpg";
class="" alt="game-of-thrones-cool-and-warm.jpg" height="0" width="970"><meta
itemprop="url"
content="https://cnet4.cbsistatic.com/img/yQzvUf9mJgs7WTpceR_21-d2Kf4=/970x0/2015/09/17/6dac9303-4006-47ac-85c9-25e55d170137/game-of-thrones-cool-and-warm.jpg";><meta
itemprop="height" content="0"><meta itemprop="width" content="970"></span>
HBO
For movies, the team is able to use the wide palette of the Digital Cinema P3
color space to create gorgeous teals, oranges and violets.
*****here's the real bottom line*****
But then comes the time to make these movies work on TV. In order to do that,
that team essentially "dumbs down" the image, removing dynamic range and
limiting the color. They get it to look the way they want, given the confines
of the HDTV system, and that limited version is what you get on Blu-ray or a
download.
*****This is the benefit of over sampling during acquisition - You can fix it
in post, mapping the source into a restricted dynamic range and color gamut. Or
to paraphrase Bert - removing the sparkle.*****
If your TV is set to the Movie or Cinema mode, this is approximately what
you'll get at home. If you're in the Vivid or Dynamic mode, the TV will then
exaggerate the colors as it sees fit. It's creating something that isn't there,
because at the mastering stage, the director and her team had to take that all
out. Is the "Vivid" version close to what they saw, or what was in the theater?
Doubtful, and there's no way to know since it's your TV's creation.
Thanks to the additional storage and transmission capacities of 4K BD and
streaming video from Amazon, Netflix and others, additional data, called
metadata, can be added to the signal. It tells HDR/WCG TVs exactly how they
should look, exactly what deeper colors to show, and exactly how bright a given
highlight, reflection, star, sun, explosion or whatever should be. It can even
adjust picture settings or put the TV in a certain picture mode automatically.
This is a huge advancement in how we're able to see images on TVs.
Technicolor's Intelligent Tone Mapping is a tool for content creators to more
easily (as in, more affordably) create HDR content. I've seen it in action, and
the results are very promising. This is a good thing, as it means it's not
labor intensive to create HDR versions of movies and shows. If it took tons of
time, and time equals money, then we'd never get any HDR content. This is just
one example of the process.
What about cables and connectors?
You won't need new cables for HDR. Current High-Speed HDMI cables can carry
HDR. The source device (a 4K Blu-Ray player, say) and TV must be HDMI 2.0a to
transmit the metadata, however. If you have a receiver and want to use it for
switching, it will need to be HDMI 2.0a as well.
The good news is many HDMI 2.0 devices released this year are getting a
firmware update to be HDMI 2.0a. Unlike the transition from HDMI 1.4 to 2.0,
there don't seem to be hardware limitations to go from 2.0 to 2.0a. If you
bought an HDMI 2.0 device this year, best to check with the manufacturer if
you're going to upgrade your gear to be HDR.
Bottom line *****the author nails it here.*****
Most experts I've spoken to, on both the content side and the TV side, are
excited about HDR and WCG. 4K itself didn't have anyone in those camps that
excited. The common refrain was "More pixels are cool, but better pixels would
be amazing."
Though breathlessly claimed as the next-generation TV evolution, 4K was
anything but. Now, with HDR and WCG, we're looking at the promised evolution,
and it should be a brighter and more colorful one.
Got a question for Geoff? First, check out all the other articles he's written
on topics such as why all HDMI cables are the same, LED LCD vs. OLED vs.
Plasma, why 4K TVs aren't worth it and more. Still have a question? Send him an
email! He won't tell you what TV to buy, but he might use your letter in a
future article. You can also send him a message on Twitter @TechWriterGeoff or
Google+.
