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FAQ: What is 4K exactly, and do I have to buy a new TV now?

Evan Dashevsky | Jan. 14, 2014
One of the most undeniable trends as this year's CES expo was 4K TVs. There were giant 4K sets, curved 4K sets, and bendable 4K sets. But all that 4K action might leave you wondering: what does 4K mean? And what effect does the onslaught of 4K have on the future of the HDTV I just bought?

One of the most undeniable trends as this year's CES expo was 4K TVs. There were giant 4K sets, curved 4K sets, and bendable 4K sets. But all that 4K action might leave you wondering: what does 4K mean? And what effect does the onslaught of 4K have on the future of the HDTV I just bought?

Worry not, my techno-curious friend. We have all the answers.

I'm reading about "Ultra HD." Is my new HDTV obsolete already?
Your TV's not obsolete, but it will soon be a generation behind state-of-the-art.

Nuts... So, what does "Ultra HD" mean exactly?
Ultra high definition (UHD) is a standard that exceeds high definition (HD). The Consumer Electronics Association defines UHD displays as having a 16:9 ratio (the same as HD) and a minimum pixel count of 3840 by 2160. HD maxes out at 1080p, which is 1920 by 1080 pixels.

Okay, so if that's "Ultra HD," what's "4K"? Is that some other format I need to worry about?
Right now, the terms 4K and Ultra HD are essentially used interchangeably. 4K is one type of UHD defined by a 2160p resolution (the minimum threshold for UHD), and it's quickly becoming the first widespread UHD standard. Another UHD standard — 8K UHD, which has a 4320p resolution (7680 by 4320 pixels)— is out there, but no one uses it yet.

It's the same as how both 720p and 1080p formats are considered "high definition" even though one has a much higher resolution than the other (marketing folks sometimes call 1080p "full HD").

4320p, huh. Wow. That's really impressive. Just remind me, what does the "p" in 1080p, 2160p and 4320p stand for again? I'm asking for a friend who doesn't understand technology as well as I do.
Progressive scan. In most everyday uses, "p" can just be thought of as referring to the number of horizontal lines of pixels a display has. So a 2160p display (4K) has twice as many horizontal lines as a 1080p display (HD). It happens to have twice as many vertical lines, too (3840 vs. 1920), for a total of 4 times as many pixels.

Okay, so 4K has a lot more pixels than HD. But is it really that much better?
4K images are composed of nearly 8.3 million pixels. Compare that to the just over 2 million found in a 1080p image, the full HD resolution produced by Blu-rays. It's nine times as many pixels as a 720p HD broadcast. That's like the difference between an 8-megapixel camera and a 2-megapixel camera.

Can I even see all those pixels?
It depends. The extra pixels make 4K images look great in the store when you're standing close to the TV. But if you expect to sit on your couch 8 feet away from your TV, you'll need a 60-inch TV or bigger to see the improvement. And the farther from the TV you sit, the bigger the TV you need in order for 4K to make a difference.

 

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