Are you ready for 8K displays?

One constant in the AV Industry is change, especially regarding display resolution and related technology. Over the past 20+years, we have seen an ever-increasing demand for displays with higher and higher pixel count. This increasing resolution trend parallels home televisions where we have all seen a fairly rapid progression from standard video with approximately 307,200 pixels of resolution in the early 2000s to recent 4K TVs with 8,294,400 pixels. This is a 27 fold resolution increase in an approximately ten-year time frame. Just as 4K has become a commonplace term, we are now seeing the introduction of 8K displays for home and professional use.

An 8K experience is big, bold, and detailed: 8K (sometimes called Ultra HD8K) is the next step forward from 4K. This takes us way beyond full HD, which is still in widespread use. In general, 8K is more: more pixels, more details, brighter color, and a wider range of brightness (and dark)levels. In-home and businesses, there is a clear trend toward bigger and bigger displays. The increase in size plays well to8K and its increased visual immersion. It’s in these larger display sizes where the shortcomings of 4K TVs can become evident. As the screen gets bigger – and you stay in the same place to view images – you need more pixels to enable crisp and sharp images. While 4K is 3,840×2,160 pixels, 8K moves up to 7,680×4,320 pixels. So 8K is about the number of pixels displayed; four times as many as 4K UHD and sixteen times the resolution of full 1920×1080 HD). Paired with features like enhanced color depth and High Dynamic Range (HDR), 8K provides a truly stunning viewing experience.

It’s important to consider that 8K and higher resolution displays have been installed in commercial and research applications for decades. However, these displays and necessary video products were done by building up a solution using an array of smaller resolution displays(like using multiple projectors, or LCD panels, or direct view LED sub-panels). The world’s first true 8K DLP projector was invented as recently as 2018. This single device projector not only saves on cost, but also on space, power, and logistic challenges as compared to ‘assembling’ multiple elements to make8K. The first 8K panel displays, a television, was unveiled in 2012 but became commercially available in 2020.

Achieving 8K Resolution

Projection
8K resolution from a single projector is now available. Select projectors will also display 3D imagery at reduced resolution.
Four – 4K UHD projectors could be stacked and blended but blending projectors requires overlapping images so 8K is not really achieved unless even more projectors are added to make up for losses during blending. Projection allows for scalable screen size, not fixed sizes resulting from tiling LCD and LED panel elements.

Tiled LCD/OLED Panels
Common panel resolutions today are HD and 4K UHD. As mentioned above, it will take sixteen HD panels or four 4Kpanels to display 8Kresolution. When panels are tiled, the panel borders create visible seams which may or may not suit the content to be displayed. Also, color matching the multiple panels requires maintenance. The final, total screen size depends on the panel size used.

Direct View LED
Using the most common pixel pitch of 1.2mm, an 8KLED wall will be about 32.0’ (9.75mm) long and 18.0’ (5.49m) high. Even with the smallest current pixel pitch available, 0.7mm, an 8Kresolution LED wall will be 20.0’ (6.1m) long. LED walls are seamless so the image is continuous.

The business case for physically large and high-resolution screens rarely changes because source images are also increasing in complexity.

Two common needs are:

• Working with high-resolution imagery(still images or video)
• Using computer applications that produce high-resolution graphics (like detailed CAD, simulations, complex analysis, and photorealistic rendering to name a few).

Can we see the difference between 4K and8K? This is the most commonly asked question about the reason and need for an 8K display. The answer is: It depends on three things:

• screen size and resultant pixel size
• viewing distance
• content to be viewed.

The first two are elements of Human Visual Acuity

Human Visual Acuity.
The human visual system is remarkable, but it has its limits. In particular, we can perceive only a certain amount of detail. So, how much detail can a person with normal (20/20) vision perceive? A comprehensive answer is complicated; it depends on which part of the visual field the image is in, the amount of contrast in the image, the amount of ambient illumination, and other factors.

As a basic guide, imagine a series of alternating black and white vertical lines on a bright display, and each line is one pixel wide. A person with 20/20 vision in a well-lit environment (conference room), centered on the screen and looking straight at it, should be able to distinguish at least 30 black-white line pairs within an angle of one degree in their field of vision. Technically, this is called 30 cycles/degree. You can also think of it as 60 pixels/degree since each black-white line pair is two pixels wide.

This is why Screen Size, Pixel Size, and Viewing Distance all work together if you want a display that makes effective use of your visual acuity.

The maximum seating distance at which you can see 30 black-white line pairs in one degree depends on the size of the pixels, which in turn depends on the resolution and screen size. For example, on a 100″ diagonal screen:

Full HD (1920×1080) resolution – each pixel measures 1.1533 millimeters on each side (assuming square pixels).

4K (3840×2160) resolutions – each pixel is half as large (0.5767 mm)

8K (7680×4320) resolutions – each pixel is 0.2883 mm.

Now, let’s look at it another way. At a given resolution, as the screen size increases, so does the pixel size. So, to have 60 pixels/degree in your field of vision, you need to be closer to a 65″ 4K screen than you need to be from a 100″ 4K screen.

What is the seating distance for any screen size and resolution that puts 60pixels in one degree of your visual field? Relative to a 100” diagonal screen:

HD – – you need to be 13.01’ back from the screen.
4K – you need to be 6.5’ back from the screen
8K – you can be as close as 3.27’

At this point, the need for 8K depends on how you will view detailed imagery on your screen.

We can see for this 100” screen example that if you remain seated 6.5’ or further from the screen, 4K resolution would be adequate, although if viewers move around and wish to approach the screen for a closer view of parts of the image(say for critical detail or touch interaction), then an 8K display would be the better choice. If 4K is adequate for your usage, but you would like a larger screen size, then an 8K display would allow you to use a much larger screen size and enjoy the same or an even higher pixel density.

8K is a good choice when a user/viewer has to get close to the screen to examine the data. 8K projection on a 100” (2.54m)screen will allow the viewer to get within 3 feet (1m) of the screen and still not see individual pixels.

Even for multiple viewers, utilizing one continuous image in full 8K resolution offers those viewers an amazing viewing experience that is ever closer to real-time human sight. Such applications range from planetariums, to theatrical and performing arts centers, to visitor attractions. These displays generate image qualities that few have ever experienced before and are certain to leave a lasting impression.

Multi-Image Capability
One big advantage to owning an 8K display is that while it certainly is four times the amount of pixel than that of 4K resolution, that means you can display four 4K content sources at the same time without any loss of visual acuity or limitations on the image. Further, you could also display sixteen sources in full HD at the time. This would be an enormous advantage in certain locations such as a sports bar/restaurant or command & control centers in which multiple content feeds would need to be displayed simultaneously (think March madness!). Mechdyne