What is 4K UHD and HDR?
Everything you need to know about 4K and HDR TVs.
4K and HDR are terms that have been tossed around a lot lately, especially since the Xbox One X and PS4 Pro support both features. But what are 4K and HDR, exactly? We provide all the important details in Q&A format down below.
What is 4K?
In regards to consumer displays, 4K generally equates to a 3840x2160-resolution panel. This means the typical 4K screen will offer 3,840 horizontal pixels and 2,160 vertical pixels. When you multiply these numbers together, you get a panel with more than 8 million pixels. This is four times the pixel density of a traditional 1080p HD panel. See the math below:
- 3840x2160 = 8,294,400 pixels
- 1920x1080x4 = 8,294,400 pixels
The term 4K derived from the fact that the film industry reached a 4096x2160 resolution standard, which is a 1.9:1 aspect ratio, but since most home monitors and TVs use a 16:9 ratio, the resolution was scaled down to 3840x2160p, which is also commonly referred to as Ultra HD.
Why should I care about 4K?
Studies show that by 2020, the majority of US homes are expected to have a 4K-capable UHD TV.
In terms of picture quality, the increased resolution provides improved image clarity and sharpness. It also allows for larger panels, since 1080p screens stretched across a large surface will begin to look blurry with their low pixel density.
Do I need a 4K player to take advantage of 4K?
Yes. There are standalone 4K players, but gaming PCs with modern graphics cards will also be able to output to 4K as well. The Xbox One S can play 4K movies, but it doesn’t have enough power to render 4K games. While the PlayStation 4 Pro is capable of running some games natively at 4K, many games use a checkerboard rendering shortcut. Microsoft asserts that its upcoming Project Scorpio console will be able to game at 4K.
Is there a lot of 4K content?
Most blockbuster movies moving forward will offer 4K Blu-ray discs (here is a list of the best 4K HDR Blu-ray movies), but UHD content on the Web is still a growing segment. 2160p video is becoming more widely available on streaming services like YouTube, Amazon, Vimeo, and Netflix. Certain high-profile 4K Netflix shows include Jessica Jones, Daredevil, and House of Cards.
What are the issues facing 4K?
Aside from the relatively small library of 4K content at the moment, you’ll need a good Internet connection if you intend to stream 2160p video. In addition, because 4K is four times as sharp as 1080p, it can be graphically demanding for gaming.
What is HDR?
HDR stands for high dynamic range. You might have heard the term as it pertains to cameras, but when it comes to display technology, it’s actually somewhat different.
Samsung showcases HDR on its TVs.
When cameras are shooting in HDR, they’re typically taking multiple exposures to highlight the dark and light information in a scene. From there, processing is used to combine the exposures into one picture to deliver a balanced image that’s more representative of how we, as humans, perceive light and color.
HDR on TVs also aims to represent colors in a more realistic way, but instead of using image processing to combine exposures together, it simply uses panels that offer a much wider color gamut compared to standard RGB TVs.
According to Nvidia, HDR can expand the color gamut by a factor of two, which amounts to roughly 75 percent of the visible color spectrum.
Why should I care about HDR?
In terms of image quality, HDR increases the contrast between blacks and whites over traditional RGB displays. This means whites will look super bright, and blacks will look very dark. Colors will also look much more lush and vibrant. For instance, onscreen fire effects will look much “warmer,” and images will, in general, have a little more pop. It’s a technology that’s arguably more noticeable than the upgrade from 1080p to 4K.
Do all 4K TVs support HDR?
No. While many HDR TVs will feature a 4K panel, not all 4K TVs will support HDR. They’re separate technologies. Having said that, HDR pairs very well with 2160p and makes good use of the greater pixel density to create a more dynamic, richer image.
What will I need to enable HDR?
Aside from an HDR-capable TV, you'll need an HDR-capable player and HDR content (this goes for movies and games). In terms of consoles, Microsoft’s Xbox One S supports HDR, and Sony eventually pushed out an HDR update to existing PS4s. In addition, the PS4 Pro also supports HDR, though it doesn't have a 4K/Blu-ray HDR optical drive like the Xbox One S. Microsoft's upcoming Project Scorpio console will also support HDR. In order to get HDR working, you’ll need an HDMI 2.0 cable.
Is there a lot of HDR content?
Not at the moment. HDR content is still in a state of infancy, even compared to 4K, but both Amazon Prime Instant Video and Netflix are working to incorporate more HDR video content. Some of Netflix’s existing, prominent HDR content includes its own Marco Polo and Daredevil shows.
Older movies and games can also be remastered to support HDR. For instance, Sony recently revealed that Uncharted 4: A Thief’s End will eventually receive an HDR update.
Are OLED TVs the same as HDR TVs?
Not necessarily. OLED TVs offer deep black levels (with each pixel serving as its own light source) and can be HDR-capable, but since they’re not backlit in the same way that popular LED TVs are, they’re not generally as bright. This means they can fail to meet HDR’s 1,000 nit brightness requirements. In order for an OLED TV to meet HDR’s requirements, it needs to have more than 540 nits of brightness and less than .0005 nits of black level.
How can I know if I’m buying an HDR TV?
The UHD Alliance was formed to create standards for HDR TVs. One standard is based on whether or not a TV can reach a certain peak brightness, measured in nits. The other standard, which is more popular for dimmer OLED TVs, is for the panel to meet a certain contrast ratio between blacks and whites.
To know whether or not the UHD Alliance has certified a TV as HDR-complaint, look for the Ultra HD Premium label.