Like 4K and 1080p before it, 8K is the next big resolution upgrade for TVs and monitors that could herald a new era of hyperrealistic visuals in movies, games, and television. It also promises to be one of the most demanding, quadrupling the number of pixels of 4K. That will stretch the limits of internet connections for streaming content, and graphics chips in PCs and consoles trying to render games at that resolution.
But like 4K, 8K isn't universally defined as the same thing. Just what is 8K resolution, really?
8K isn't always 8K
Technically, 8K resolution is any display with a resolution width of approximately 8,000 pixels. That loose definition means that there are a number of different "8K" resolutions that have quite distinct horizontal and vertical pixel counts, depending on their aspect ratio.
What is 8K resolution to most, though? It's 7,680 x 4,320, often called 8K UHD. That's the highest resolution defined by the International Telecommunication Union (ITU) in its original 2012 Rec. 2020 standard recommendations. That also defined a number of other standards, including 4K (3,840 x 2,160) various frame rates from 120p down to 24p, as well as a number of color bit-depths.
The ITU defined 8K resolution uses the aspect ratio of 16:9, the most common aspect ratio of mainstream TVs and monitors. With other mediums, platforms, and display-types, though, there are also other 8K resolutions which are important too. 16:10 is a popular display aspect ratio for some monitors, and for 8K displays that would mean a resolution of 8,192 x 5,120. Fulldome cinemas, designed to provide a glasses-free, immersive, VR-like experience, utilize a 1:1 aspect ratio, so would use an 8K resolution of 8,192 x 8,192. That works out to more than double the overall pixel count of the UHD 8K standard, so there is some real variance in 8K resolution depending on the setting and display type in question.
At its core though, 8K resolution, as described under the ITU recommendations, has double the pixel width and height of 4K, which means it has four times the overall pixels and 16 times the overall pixels of 1080p. That makes for a more detailed image, a much more nuanced image, and one that gets very close to photo realism when best-taken advantage of.
But it is a major investment and the amount of 8K content out at this time is rather limited. If you ever wondered, can the human eye see 8K, or whether it's worth spending your money elsewhere instead, you need to ask yourself one important question...
Is 8K worth it?
With every new display technology that becomes available, it's important to ask whether upgrading to it will dramatically improve your movie watching and game playing experience. The jump from SD to 720p, and then 1080p HD was huge and well worth it. 1080P to 4K isn't as noticeable, but it's still worth upgrading to and many people already have. While as of 2018, only 31 percent of U.S. households had a 4K display of any kind, the number of 4K TV owners is trending upwards every year, and faster than most expected. 8K may well follow suit in due course.
But can the human eye see 8K? While that question doesn't take into consideration the different ways in which organic eyes work compared to displays (we don't see in pixels) the human eye can effectively notice differences up to 40 megapixels. A typical 8K image is around 33 megapixels, so there is still room for improvement, even at 8K. But you may want a bigger TV to see all the benefits.
Already on 4K TVs, you'd need to be within a couple of feet of the display to notice the lines between the pixels, and therefore the individual pixels themselves. While 8K does deliver a more detailed image, arguably its best feature is enabling similar detail levels at even larger screen sizes.
This has to do with pixel density, commonly measured in Pixels Per Inch (PPI). If the resolution amounts to the total number of pixels on a screen, then you’re going to need more pixels to fill up a larger screen without losing quality. Otherwise, that same number of pixels will need to be stretched across a larger space. The graph below shows how pixel density (and therefore quality) changes with different sized screens at a given resolution. You can see that 8K and maybe 4K are the only viable options for a 100-inch display. On a 1080p display that size, there would only be around 22PPI, making for an extremely ugly image. While there is no defined range for optimal pixel density, it is generally agreed upon that 150PPI is the lowest you’d want to go while anything over 400PPI can’t be detected by the eye.
It is also important to take viewing distance into consideration here. As seen on the chart below, displays of all resolutions look the same at longer distances. Higher resolution displays allow you to sit closer while still noticing the quality of a display. Sitting 15 feet away from a 105-inch 4K display will give you the same quality experience as sitting 15 feet away from a 50-inch 1080p display but that seems a little too far away, doesn’t it?
8K has the potential to offer a better quality picture at larger display sizes and for those who like to sit very close to their display for added immersion. While 8K content is still quite limited in 2020, many 8K TVs provide upscaling, which helps bridge the gap between content and screen while the technology becomes more ubiquitous.
What do you need for 8K?
Whether you want to be on the cutting edge, or just want to buy the biggest TV possible and don't want to sacrifice image quality in doing so, 8K is the display tech to opt for. But you'll need to make sure that your hardware is up to snuff, as you need some specific equipment, like 8K capable cables, to enjoy the full richness of an 8K TV or display.
The first step is getting hold of an 8K display. There are a few 8K TVs around and a couple of 8K monitors, all of which are super high-end and worth considering. They're expensive, but reviewing them based on their capabilities and specifications goes beyond the scope of this article.
You then need an 8K source, which as of early 2020, is quite difficult. There are no 8K physical media – and quite likely never will be – but streaming is the future of entertainment, and 8K is very much part of that future. While most of the major streaming platforms, don't support 8K content at this time, it is coming down the pipe. For example, the new Xbox and PS5 being released in late 2020 will support 8K content. (Downloadable, most likely- don't expect to pick up 8K Blu-ray disks). Also, the 2020 Tokyo Olympics will be broadcast in 8K, giving early adopters a real treat for the eyes this Summer.
YouTube has become the first streaming service to actively support 8K. While it's not present on Amazon Prime or Netflix just yet, it's only a matter of time. 4K is becoming more common all the time, so expect some showcase 8K content in the future as filming for it increases in popularity.
Your 8K TV may have some smart features which allow it to stream 8K natively from YouTube too, but for the most control over your 8K experience – and one that will open up the potential for 8K gaming too, if you want it – you should connect your TV to an 8K ready PC. There are few systems being sold for such purposes or with such naming conventions just yet because it's a very niche market, but we can make some recommendations.
The most important component you'll need is a high-end graphics card. At least an Nvidia RTX 2080 Ti, and preferably something even more powerful like the Titan RTX. The best cards in the world for viewing 8K video would be Nvidia's professional cards from its Quadro RTX series, but they won't be so good for any 8K gaming you're considering. You may be better off with multiple RTX 2080 Tis instead.
You'll also want a high-end processor, plenty of memory, and, if you plan to download 8K content for later playback, the fastest storage you can buy. That's going to be a PCIe 4.0 NVMe SSD.
Once you have your 8K capable PC ready to roll, you'll need to connect it to your 8K display. The only cables that support that resolution at this time are high-end DisplayPort 1.4 cables, or HDMI 2.1 cables, from a reputable seller like Cable Matters. Cable quality for such a data-dense stream is of paramount importance, as you'll want to guarantee that your cable isn't causing any signal degradation, which would really take away from your 8K experience. The newest generation protocols of DisplayPort 1.4 & HDMI 2.1 are a strict requirement because previous generations don’t support the bandwidth required for an 8K display.
You could also opt for an active DisplayPort cable if you want to have your display at a greater distance from your 8K machine. Forgoing even further, there are DisplayPort repeaters you can use, and if you find yourself needing to use a different cable type for whatever reason, there are USB-C adapters and options for splitting the signal between multiple outputs.
If you're planning to stream 8K content from the internet too, you'll need a high-speed fiber connection, as nothing else is going to be able to keep up.
So, what is 8K? It’s the next stepping stone on the ever onwards march towards photorealistic visuals in movies, television, and games. But even the best 8K TVs aren't quite like looking through a window just yet. So, what's after 8K TV?
No one knows for sure, because we're still a long way from even 4K becoming a ubiquitous resolution in modern displays, let alone 8K. But there are some ideas about what we can expect. There's the possibility of even greater resolutions – 16K is one such potential eventuality. We've already seen some examples of this from technology companies like Sony and Touch Taiwan, both of which have debuted massive 16K displays in recent years.
AMD has suggested it will target 16K support with its future graphics cards to make it possible to not only render video at such resolutions but even eventually support virtual reality headsets that leverage such pixel-dense displays.
Other visual enhancements could prove more popular instead, though. HDR and high frame rates have been more of a focus for movie viewers and gamers in recent years, so it could be that added contrast, color depth, or augmented reality are of more interest to potential buyers than yet another giant leap in resolution.
What's after 8K? More of the same, but also a little extra. There are lots to be excited about in the display space, but it's going to be a while before 8K is even remotely commonplace. Let alone whatever comes after.