Welcome to the HDR TV wars
By Ajith Ram January 10, 2017
- Two competing standards in the consumer HDR TV space
- Standard and HDR images are immediately distinguishable
EVERY few decades, the consumer TV industry sees a small upheaval as an impressive new technology emerges from the R & D labs. In the previous decade and a half, we witnessed the shift from bulky CRT screens to slim LCD ones. This transition also witnessed the fall of Sony as a TV manufacturer and the rise of the Korean giants like Samsung and LG.
It is possible that the next TV revolution is upon us with the advent of HDR TVs. But the emergence of this tech also brings a high degree of consumer confusion. Read on to find out what you need to know before you rush out to buy a new HDR TV.
What exactly is HDR?
HDR stands for high dynamic range imaging and is a photography practice recently introduced to smartphones like the iPhone and some Android devices. HDR, as its name implies, is a method that aims to add more 'dynamic range' to photographs, where dynamic range is the ratio of light to dark in a photograph.
Instead of just taking one photo, HDR uses three photos, taken at different exposures. In the case of HDR on smartphones, the phone will combine these photos to create a final image. The result is something that is closer to what your eyes see, rather than what your camera sees.
This is why, when you turn HDR mode on, your phone takes a little longer to take the photo. It is actually taking three pictures, rather than just one. See the image below for the difference between HDR and non-HDR images.
The world of consumer TV has finally caught up with still photography. Today, almost all the LCD manufacturers are selling HDR TVs. And they are desperate to make it a success.
Ever since the HDTV standard emerged in the mid-'90s, TV manufacturers have struggled to come up with new features that are as impressive as the transition from CRT to LCD. One of this was the short-lived 3D TV craze. Thanks to bulky glasses and lack of content, it went the way of the Dodo.
A similar fate awaits the 4K TV standard. Consumers with smaller living rooms are not interested in buying large screen TVs and for them, 4K does not make a huge difference.
But HDR TVs might just be golden apples that the TV manufacturers are looking for. HDR images are brighter and more colourful enough to the discernible to the untrained eye. And unlike 4K, even smaller screen TVs can display the quality difference between normal and HDR images.
High dynamic range is a blend of several variables - luminance, colour gamut and colour range. In terms of luminance. HDR screens are not just bright. The most important factor is the range between the deepest blacks and the purest whites.
Modern LED screens have a backlight which is on all the time. This prevents them from displaying 'pure' blacks. This is also the reason why some OLED TV manufacturers like LG are keen to advertise the intensity of their black pixels. Even though the OLED TV might not be as bright as the LED one, it might appear brighter due to the increased range between the black and white pixels.
For a more in-depth explanation of dynamic range, see this article by Dolby.
Currently, there are two HDR formats slugging it out in the consumer TV space: HDR-10 and Dolby Vision. Naturally, the standards have a few things in common, including support for 10-bit colour depth, a jump to the Rec.2020 colour gamut standard and uncapped luminosity levels.
In theory, Dolby Vision is the more impressive format because it supports 12-bit colour depth. The increased colour depth should remove all traces of colour banding which might occasionally appear with 10-bit colour.
As luminance ranges grow, movie directors might choose to control luminance with greater granularity. Dolby Vision is perfectly setup for this future.
But current high-end consumer TVs are not yet capable of displaying the difference between 10-bit and 12-bit colour effectively. So the extra quality offered by Dolby Vision will not be perceptible to a buyer.
Like all Dolby devices, TV manufacturers need to pass a certification process and include proprietary processors. For now, all you need to remember is that if you buy a TV set that supports Dolby Vision, it also supports HDR-10, but not the other way around.
Also, keep in mind that you will not find any HDR-10 logos on any screens. Instead, you are likely to find logos such as Ultra HD Premium, and UHD Alliance certified. But some HDR TV manufacturers like Sony are not part of this consortium.
Due to the price difference, it is possible that HDR-10 TVs might ultimately win the standard war against Dolby Vision. We just have to wait and see.
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