What is a 4K TV?

Wondering about the new HD format called Ultra HD and what is 4k? No problem – we've got your answers. Here's what you need to know.

What Exactly is 4K or UHD?

4K explanations always focus on pixels, because that's where the big news is. The HDTV of yore - the traditional flat screen - was almost always maxed out at a resolution of 1920 x 1080 pixels, more affectionately referred to as "1080p". That was as many pixels as you could squeeze onto the display's surface, and that was as much image data as the hardware made to display it could deal with at any given time.

A 4K TV, on the other hand, has 3840 x 2160 pixels, or exactly twice the resolution of 1080p. Thankfully, the devices we love and hold dear can successfully process that much data nowadays, and the result is a resolution with many, many more pixels that are able to form a much clearer, sharper picture than a standard CRT.

Read: Best LED TV 2016

4K resolution on the other hand is becoming a very big deal, in part because 4K TVs are dropping in price. Eventually, they will replace all of our older 1080p HDTVs and become the new standard for high definition, so get used to seeing "4K" on your cable packages, movies, video streaming, and more.

All 4K Isn't Created Equal

Right off the bat, it's important to note that when we talk about "4K" resolution, there are actually two different types of 4k that are incorrectly grouped under the same umbrella of terminology.

The first is that what we refer to as "UHD 4K" almost always applies specifically to 4K rollouts in TVs, computer monitors, and projectors that support the 3840 x 2160 resolution displayed in the 16:9 aspect ratio. If you were to quiz a Hollywood director on what they think 4K looks like, instead they'd refer you to what's known as "DCI 4K", or the Digital Cinema Initiative.

Opposed to 4K content that's recorded with the express purpose of being viewed on a standard 4K TV, DCI 4K is actually 4096 x 2160 pixels tall and across at a 19:10 aspect, or about 10% more visible space than what you'd get out of UHD 4K.

You could fill an entire tome with the reasons why the film and consumer electronics industries have split on the issue, but boiled down to a sentence: it all comes down to compatibility. For most films that are viewed in a theater, the 19:10 aspect ratio fits perfectly. For movies and shows at home however, because screens that support 1080p have been stuck on 16:9 for so long, many 4K TV manufacturers opted to simply stick to that resolution instead, making it easier for consumers to view any content (1080p, 4K, or otherwise), in a single, universal aspect that was compatible with the widest number of screens right from the get-go.

Telling the Difference

We explain what is 4k and how it works[/caption]

Theoretically, UHD 4K resolution TV is still a huge leap from standard HD, the same sort of jump that took place when standard 480p 3:2 aspect gave way to 1080p (more pixels = better, right?). But how does this look in practice? Is the difference really that noticeable?

Well, sort of; it all depends on who you ask.

For the Average Joe, 1080p HD is still really, really good. In fact, it's so good that it actually reaches the limit of what the human eye can deal with. Unfortunately, this means that the upgrade to 4K technology may be difficult to notice unless something changes.

First, you can get a bigger screen. If you stick with a smaller screen, you probably won't be able to tell the difference between 1080p and 4K television, because of how the density of pixels affects each eye on an individual basis. When Apple first made waves in the press with their "Retina" displays a few years back, everyone was left wondering what "retina" actually meant. In the company's own terms, it's the "eye's ability to discern the separation between one pixel and the next at a standard viewing distance", which means that if you hold your iPhone, iPad, or Macbook at a "readable" distance, you shouldn't be able to see where one pixel ends and another one begins.

Are Retina displays 4K? Not even close. The difference here is that big screens gives the pixel density of 4K more room to tell its story, and makes it easier to spot the change when upgrading to a higher definition. 4K is a standard that packs in as much detail as possible into every square inch of available space, and does away with the flaws you might find if you're sitting closer to a 1080p screen than is recommended in the manufacturer's manual.

It's worth noting here that other technologies may make the picture boosts showcased 4K more apparent, too. Upgrading an LED TV may lead to marginal improvement, but the effect may be much more noticeable if you also switch to an OLED screen.

Accessing 4K Content

4K has been around for sometime, but exactly what "4k" is is still a looming question[/caption]

Last, it's imperative to be able to recognize the difference between a "4K television" and "4K content". While the majority of 1080p-scaled content is in a transition stage toward 4K, finding compatible video may prove a challenge. There are certain blips of Netflix content that's available in 4K, but it's fewer than it is farther in between at this stage ion the game. Amazon also offers limited 4K streaming, though whether or not you'll be able to receive it is highly dependent on the device you're trying to stream to.

Other services, like Sony and Samsung's individual video services offer 4K options, but again it needs to be said that even if you're getting 4K streamed, it's not the "true" 4K that you'd find being pumped straight out of a $250,000 camera on the set of a major summer blockbuster. Any 4K streaming, whether through Netflix or otherwise, is being compressed in order to get from the website's servers onto your screen within a reasonable amount of time.

In order to achieve the absolutely maximum of what a 4K set-top TV is capable of, you'd have to grab a compatible Blu-Ray 4K player (which isn't even available to the general public yet). As time goes on, Blu-Ray 4K is destined to become as ubiquitous as the 1080p format that spawned it, but until then, any "4K" you think you're getting from Netflix won't look anywhere near as good as what you're watching on the screens down at your local Best Buy.