What Is 4K (Ultra HD)?
You may have seen a number of new TVs, camcorders, and other products sporting a 4K logo, and movies shot in 4K have been playing at movie theaters for years. But what exactly does 4K mean (aside from the stock memory in a Radio Shack TRS-80, for the aging geeks like me in the audience)? Is 4K something you should get today, or at least soon enough that you should hold off on buying, say, an HDTV or Blu-ray player? Is it something you'd evenwant? Here's everything you need to know about 4K—for now, at least.
What Is 4K?
Ultra HD (4K), or Ultra High Definition, is the next big step in HDTV resolution. The Consumer Electronics Association (CEA) defines an Ultra HD television as one that displays at least 8 million active pixels, with a lower resolution boundary of at least 3,840 by 2,160. There are multiple varieties of 4K digital content ranging from 3,840 by 2,160 to 4,096 by 3,112, but the 3,840 by 2,160 resolution is the most consistent number we've seen and the standard resolution most UHD/4K HDTVs and monitors have settled on. It's a nice, even number, doubling the horizontal and vertical pixels offered by 1080p (1,920 by 1,080 pixels), the current standard for high definition.
Collectively, the format was originally known as 4K, and while the CEA officially changed its designation to Ultra HD (UHD for short), the 4K label has stuck and both terms are effectively interchangeable.
How Is 4K Different Than 1080p?
Depending on the variety (discussed above), 4K generally offers four times the resolution of standard 1080p HDTVs. Even so, 4K content will still be compressed for home use, as an uncompressed two-hour movie playing at 30 frames per second would require 55TB of storage just by itself, according to an excellent post from Michael Cioni, who acted as digital intermediate supervisor on The Girl With the Dragon Tattoo.
4K video also takes a solid 1Gbps path for reliable playback (unless it's compressed in some way), which requires fast hard drives and faster-than-usual Internet and network connections. Netflix, for example, recommends a 25Mbps connection for streaming its (compressed) 4K content. The HDMI connections on your current devices might not be enough to show 4K video at its smoothest; most entertainment devices and HDTVs use HDMI 1.4, which supports an Ultra HD picture at 30 frames per second. HDMI 2.0, which is increasingly common for current 4K HDTVs, supports Ultra HD at 60 frames per second. Like the display technology itself, it will take some time for the HDMI standard to become common enough for both HDTVs and media players.
In terms of screen real estate on a desktop, 4K makes a tremendous difference; check out the Editors' Choice Dell UltraSharp 32 Ultra HD UP3214Q if you've got the cash to drop. But even when watching movies, it can be pretty clear. While some regular viewers struggled to see the difference between 1080p and 720p in smaller television sizes, it was much more obvious on 50-inch and larger TVs. 4K is another significant jump in terms of clarity and detail, especially since people are becoming more and more used to the incredibly tiny pixels displayed by today's Retina-style HD screens on mobile gadgets. This is a major factor for large HDTVs as well, since 55 inches has become a low boundary for just how big a big screen can get.
What 4K HDTVs Are Out There Now?
4K HDTVs have been hitting the market for a few years now, and are finally starting to become affordable. It is now possible to find a good-sized 4K display for under $2,000, although larger, high-end models from big brands can still run much higher than that.
Last year's Samsung UN65HU8550FXZA, for example, is an excellent 65-inch 4K television available for $3,200. Vizio's 65-inch P652ui-B2 isn't quite as impressive, but you can find it for about $1,700. Those are prices for very large screens; once you go below 55 inches 4K becomes even more affordable, with retail prices consistently dipping below $1,500.
Is There Even Any 4K Content You Can Watch on an HDTV?Netflix has really helped expand the 4K content available to consumers, with major shows like Daredevil, House of Cards, and Breaking Badavailable through the service in 4K. You need a 4K television that can stream Netflix 4K content (or an Nvidia Shield Android TV) and a fast Internet connection, but there are at least some ways to watch 4K video. YouTube and Amazon Instant Video also support UHD content, though commercial television and movies are still limited.
Back in 2012, the first 4K digital movie available for purchase was TimeScapes, a beautiful 50-minute film of night sky cinematography. It was shot on a RED Epic camera (pictured below) in 4,096-by-2,304-pixel resolution. A $9.99 1080p copy is available on iTunes, but full 4K versions come in $99 and $299 USB-stick varieties, with an even sharper picture on the $299 version.
As a rule, movie studios now routinely deliver 4K movies to commercial theaters, but none are available for home purchase yet in that format. A professional-grade camera like the Canon EOS C500 records 4K content, but at $26,000, it's not exactly an impulse buy. A number of smartphones and action cameras have brought 4K recording to the masses, but don't expect the quality to approach the level of a theatrical picture; consider it a marketing gimmick more than anything else. More realistically, prosumer products like the $5,000 JVC GY-HMQ10 or the $4,500 Sony 4K HandyCam Camcorder FDR-AX1 record properly specified 4K video, but they're far from inexpensive. The $2,500 Sony Alpha 7S does it as well, but only with an optional external recorder.
Bottom Line: Do You Need 4K?
You don't need 4K yet, but it's becoming reasonable to consider upgrading. The content still isn't there, but a solid 4K screen today costs as much as a high-end 1080p HDTV did just two years ago, so it's gone past the initial stage of incredibly expensive early adoption.
It's already pretty clear that 4K won't end up like the 3D fad in there not being enough good content available to watch, even years after the technology's debut. 4K has a much better chance of becoming mainstream, because it doesn't need special glasses, and because movie studios are already defaulting to shooting in it and promising a broad base of available content down the line.
For more, check out The 10 Best HDTVs.
