So Consumers Union is entering the HDR arena...
Buyers beware!
Regards
Craig
http://www.foxnews.com/tech/2016/07/19/what-is-hdr-tv-and-should-get-one.html
What Is an HDR TV, and Should I Get One?
High dynamic range, or HDR, is one of the biggest TV buzzwords you’ll come
across this year. While 4K (the other big buzzword right now) is about adding
more pixels, HDR is about creating better, more dynamic-looking pixels. It does
that by boosting contrast and brightness, and providing a wider range of colors
than you can get with current 1080p content and displays.
This is the first year that we've seen a large number of TVs with HDR
capability. And now that we've had a chance to test dozens of them, it's clear
that's there are big differences in HDR performance. That will make it
difficult for shoppers to know which TVs can show HDR images in all their
natural-looking glory, and which offer only marginal improvements in picture
quality.
If you're in the market for a TV with HDR this year, here’s what you need to
know.
What Is HDR?
The concept of high dynamic range isn't new. We’ve been talking about it in
audio for decades, where it refers to the difference between the softest and
loudest sounds in a musical passage. In still cameras, HDR combines the best
elements of several photos of the same scene, shot with different exposures.
But with TVs, it’s all about improving the contrast between the darker and
brighter parts of a scene.
To enjoy an HDR experience, you need content—movies and TV shows—that have been
mastered with HDR, plus a display that can reproduce it. Most of the
HDR-enabled content right now comes from streaming services such as Amazon and
Netflix, as well as from new Ultra HD Blu-ray players and discs. For streaming
4K videos with HDR, you need a relatively fast broadband connection, of at
least 18 to 20Mbps. (You can check your broadband speeds at speedtest.net)
Ultra HD Blu-ray discs, which have a consistent 100Mbps data rate, provide the
best 4K picture quality currently available.
When presented with HDR content, TVs with HDR can display a wider range from
black to white, so you can see more details in the very darkest and brightest
areas of the picture. You’ll also see “specular highlights,” which are the
momentary glints of brightness that appear on illuminated objects, such as the
reflections off a car's chrome bumper or a Roman gladiator's armored breast
plate. Without HDR, those highlights wouldn't be any brighter than other bright
objects in the scene.
To achieve these effects, top-performing TVs with HDR are brighter than regular
sets, though HDR isn't just about increasing a TV's overall brightness.
Instead, it's about being able to provide the necessary higher levels of peak
brightness when the scene calls for it.
Check out the fireworks scene in the photo at the top of the page, for example,
which was provided by Dolby to show the difference between high and standard
dynamic range. In the standard dynamic range part of the image, on the right,
the image seems overwhelmed, with indistinctive masses of brightness and
indistinct clouds of smoke. But on the left you can see clearly defined sparks
from the fireworks, different colors and intensities in the clouds of smoke,
and details in the dark background.
One other thing: Technically it's not part of HDR, but most TVs with HDR also
have wider color gamuts, meaning they can display a wider range of colors than
regular sets. HDR can give this extended range of colors greater intensity.
When done well, TVs with HDR and wider color gamuts offer brighter, more
dynamic-looking images with greater contrast, more gradations of colors, and
lighting that appears more lifelike.
Big Differences in HDR Performance
Unfortunately, though, what we've found so far in our labs is that while some
HDR-capable TVs produce super-bright, colorful HDR images, others don’t. How
can this be? Well, some televisions have the hardware to really take full
advantage of HDR. Others can only read the HDR metadata, which is the
information embedded in the digital signal that tells the TV how the image
should be displayed. These sets, which are being called "HDR-capable" or
"HDR-compatible," then try to accommodate the instructions as best they can,
based on the TV's capabilities.
Brightness, for example, is a big challenge. Top-performing TVs with HDR can
hit anywhere from 500 to 1,000 nits, the unit used to measure brightness. But
some so-called "HDR-compatible" TVs can only produce 100 to 300 nits, so they
don't have the headroom to produce the peak levels of brightness required for
HDR. As a result, we have some TVs in our labs that use the acronym HDR in
their packaging, but that don’t look much different from standard dynamic range
sets.
There's one other wrinkle: There are actually two types of HDR technology.
Fortunately, one of them—called HDR10—has been adopted as a baseline standard,
so it’s included in every TV with HDR we’ve seen so far, with the exception of
Vizio sets. It's also the only format currently supported by Ultra HD Blu-ray
players. The other type is called Dolby Vision, which is positioned as an
enhanced version of HDR10. So TVs that support both formats, like those from
LG, can use Dolby Vision HDR when that content is available, or HDR10 when the
content is in that format. (Vizio has said it will offer a firmware update
later this year that will let current models play HDR10 shows.)
Which Models Have Great HDR?
So how can you tell if the TV you’re considering is able to deliver the full
HDR experience? It's not going to be easy. To help reduce confusion, the UHD
Alliance—a diverse group of TV makers, Hollywood studios, distributors (such as
DirecTV and Netflix), and technology companies—has created performance
specifications for "Ultra HD Premium" TVs. Sets that pass a certification
process can use a new Ultra HD Premium logo on packaging, so you'll know they
can deliver top-level UHD (aka 4K) performance in various areas, including HDR.
The problem is that while some brands, including LG and Samsung, have adopted
the logo, others, including Sony and Vizio, aren’t submitting their TVs for
certification. The same is true for many 4K sets from lesser-known brands that
aren't going through the certification process. Until we test them, there's no
way to know how well these sets will perform.
That’s why we’re developing more HDR test patterns and utilizing real-world HDR
clips that can help demonstrate the differences in performance for those
considering one of these sets this year. Right now every TV with HDR capability
in our TV Ratings (available to subscribers) has some statement about its HDR
performance as part of the set's Detailed Test Results. We're hoping later this
year to be able to add some type of HDR score to the TV's evaluations.
