This article explains that all 4K sets are certainly not HDR, that most HDR
sets are LEDs, and that HDR from LED sets is even brighter than what we can
expect of OLED. Although OLED has blacker blacks, because the pixels themselves
light up. As opposed to being backlit.
Obviously, the cheap and broadly available 4K sets are not going to be HDR, at
least not yet.
And this article was written almost a year ago, before 4K sets became so
affordable.
Bert
---------------------------------------
https://www.wired.com/2016/01/what-is-hdr-tv/
What You Need to Know Before Buying an HDR TV
Tim Moynihan Gear
Date of Publication: 01.20.16.
Time of Publication: 1:28 pm.
In the world of new TVs, the goalposts are always moving. As soon as you feel
safe splurging on a new set, another reason to hold out comes along. First
there was 3D. Then 4K. Let's not forget about OLED and quantum dots, then
cheaper 4K and cheaper OLED. This year is no exception, with another new
technology offering another reason to hold your horses. It's called HDR video,
which is short for "high dynamic range."
HDR is not about extra pixels. Every set capable of handling HDR video already
can display 4K video. Instead, HDR makes images with widely varying lights and
darks look better on your screen. It's great! You totally want it. But like
most nascent technologies, barriers abound for early adopters. From high prices
to a dearth of video sources, there are many things to consider before you buy
into HDR.
What Is HDR Video?
If the "HDR" acronym sounds familiar, it's because you've seen it as a setting
in your smartphone camera. The results there are not great, which means you
probably think HDR sucks. For still photography, HDR is a handy (if overused)
workaround to a common problem: It brings out details in the light and dark
areas of a scene, usually by capturing multiple images at different exposures
and merging them. The problem is, such photos often look airbrushed and fake.
HDR video is different. It looks very realistic, with gradations and nuances
closer to what's seen in real life. It can get bright enough to simulate light
reflecting off chrome and dark enough to look like an oil slick. In both cases,
you still see fine detail and subtle shades. HDR doesn't fake the contrast with
stupid filters and weird halo effects. Instead, it uses new panel technologies
with a wider color palette in concert with specially encoded video.
For that reason, you need a specific type TV to see HDR video properly, and you
need a specific type video source, too. In the best case scenario, you will see
deeper and more accurate colors, and lighting effects will appear more lifelike.
How Are HDR TVs Fundamentally Different?
HDR isn't tied to a certain type of display technology, but almost all HDR sets
thus far share a few traits. Vizio, Sony, Samsung, Panasonic, LG, TCL, and
Hisense all have HDR-capable TVs that are essentially super-powered LCD 4K
televisions. These sets can get really bright-bright enough that looking at an
onscreen sun or explosion can make you squint. These panels' backlight systems
crank up to more than 1,000 nits-by comparison, most LCD HDTVs put out around
300 or 400 nits. Why so bright? With such a high peak brightness, the contrast
between light and dark (or light and lighter) areas of the scene are more
pronounced.
Also, most HDR televisions aren't OLED sets. They use LCD panels, since they
can get much brighter than OLEDs. However, because OLEDs don't have backlight
systems (each pixel turns on and off individually on an OLED) they can get much
darker, and therefore produce deeper blacks. Earlier this month, LG and
Panasonic both announced new 4K OLED TVs that can display HDR video.
What About Colors? Are They Any Better on HDR TVs?
Yes! There are waaay more colors on these high-end 4K TVs.
That's because both content and TVs are moving far beyond the color space and
bit depth of traditional HDTVs. For displaying colors, HDTVs stick to a
25-year-old specification called Rec. 709. It's an 8-bit color space
recommendation made by a TV trade group. It's as old as Windows 3.0 and season
one of The Simpsons. It's archaic, and it's been supported throughout the
entire HDTV era. Now we have a new spec: 4K TVs and content will take aim at
the 10- to 12-bit Rec. 2020 color space, which represents more than 60 times as
many distinct color combinations as Rec. 709. More than a billion of them,
actually. The Rec. 2020 color gamut is even wider than the DCI-P3 color space
defined for professional digital projectors (which is also much wider than Rec.
709).
From filming to mastering to distribution to display, we're talking about an
end-to-end pipeline that produces a far better picture. Content can be mastered
to take advantage of a wider color space, extra metadata is piped to an
HDR-capable TV to define how it looks, and color-tuning technologies such as
quantum dots can help it display accurately. The combination of 4K resolution,
extreme brightness, improved contrast, and more colors will be what makes HDR
video look spectacular-even if the "HDR" trick itself is only part of the sauce.
Man, How Do I Make Sure My New TV Does All That?
There's a badge now! The UHD Alliance, a group of TV manufacturers, content
providers, and distribution companies, will begin issuing an "Ultra HD Premium"
stamp of approval for certain TVs. These badges will be reserved for the
"five-tool players" of the TV world, sets that provide a combination of
tack-sharp resolution, high dynamic range, and very wide color gamut.
To qualify, a TV must have a display resolution of at least 3840×2160 (that's
4K), support 10-bit color, be able to handle sources that use the Rec. 2020
color space, and be able to display at least 90 percent of the DCI-P3 color
space. In terms of dynamic range, the Ultra HD Premium badge accommodates both
LCD and OLED displays. For an LCD, a qualifying TV must have a peak brightness
level higher than 1,000 nits and a black level less than 0.05 nits. For an OLED
to qualify, it must have a peak brightness of at least 540 nits (remember,
OLEDs cannot get super bright) and a black level less than 0.0005 nits
(remember, OLEDs can get super dark).
Those things are all impossible to gauge in the store, so the UHD Alliance
tests all the parameters in a lab. If a set passes the test, it gets a logo
that looks like this:
OK. So What Do I Watch on My New Super TV?
As you might expect, 4K HDR video is harder to find than. normal 4K video. And
depending on the source and your set, even when you do find it, you've got
another format war to think about. Hooray, a new format war!
Perhaps the best-known HDR format is Dolby Vision, a proprietary format that
requires a compatible set with a Dolby Vision decoder built in. In terms of
future-proofing, Dolby Vision is compelling: It can handle 12-bit color
depth-68 billion colors-and it's designed to support backlight systems that are
at least four times more powerful than any current HDR TV has. Vizio was first
to market with a Dolby Vision-compatible TV-the Reference series sets from late
last year-and LG, Philips, and TCL all trotted out Dolby Vision TVs at CES
2016. You can find Dolby Vision content on Vudu right now, and Netflix will
offer it "soon." Some 4K Blu-ray discs will be Dolby Vision-mastered, too.
There's another format called HDR 10. It will be the format supported by all 4K
Blu-ray discs, and the UHD Alliance is backing it, too. (Dolby is part of the
UHD Alliance, which means some of those meetings must get pretty awkward.) HDR
10 "only" supports 10-bit color, but there will certainly be much more HDR 10
content out there by the end of the year. Some sets can handle both formats:
LG, Philips, and TCL both say their new sets will play both Dolby Vision and
HDR 10 content.
Sounds Messy. Should I Wait?
Yeah, probably.
Is There a Classic Rap Song That Explains All This?
Yeah dawg.
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