Are 8K TVs useful technology?

I see some new televisions advocating 8K, so who is going to run out and buy one?

4K means that the content of a display is roughly 4,000 pixels wide. My Sony Bravia 4K display has 3,840×2,160 = 8,294,400 pixels. An 8K display has four times as many. It might have been easier to say 4K=9 megapixels, and 8K=35 megapixels. At least its terminology people mostly understand. More pixels of course mean a crisper picture, because it contains more detail – great for those nature scenes of a drone flying over a landscape, actually not so great for peoples faces, where details show every flaw. 4K is slowly making inroads, especially commercially, but it might take a decade before it even becomes the norm. Part of the problem lies in a lack of digital infrastructure. Think about the bandwidth alone. 4K requires something like 15-25 Mbits/s for every stream, 8K could require upwards of 80-100 Mbits/s.

Look more pixels are good, there is no doubt about that. But technology does not always mesh with the optimal abilities of humans. The resolving power of the human eye decreases as the distance between the eye, and the object being viewed increases. The benefit of higher resolution TVs is that you can view them from a closer distance (before pixelation occurs). That means you can sit closer to a 4K TV than you could a 1080p TV. Consider a TV with a 40″ screen. A 1080p resolution would have an optimal viewing distance of 5.2ft, a 4K resolution 2.6ft, and an 8K resolution 1.4ft. But who wants to watch a TV from 1.4ft away? If the average viewing distance in a house is 6-8ft. So if you sit between 1.4-2.6 ft away from an 8K TV, you would see some, but not all of the added detail in an 8K image. If you sit more than 2.6ft away from the TV, the 4K and 8K TVs would appear identical.

It’s analogous to a screen on a tablet. View a 16MP or a 36MP image on such a device, and likely you will perceive very little difference. The difference in resolution detail only shows up on much larger screens. The same is true of 4K and 8K. You might get a benefit from 8K if you view it on a 100″ TV, but then again, who really cares that much? Cameras are no different. Canon’s new DLSR sensor is 50.6 megapixels, or 8688 × 5792 pixels – it won’t make an 8×10″ photo look any better than a 16MP sensor. Upgrading technology is useful if there is an inherent benefit to the user. Considering how little content there is for 4K, maybe 8K will be bypassed for 16K, or 32K? These resolutions will make little impact for the home user, unless entire rooms are dedicated to install huge wall-TVs. Filming in 8K likely makes sense for filmmakers, to see on the big screen.

Technology for the sake of technology?