8K vs 4K – double-blind study shows hardly any differences

by Tobias
17. January 2023

In a double blind 8K vs 4K study, Warner Bros, along with Pixar, Amazon Prime Video, LG, and the American Society of Cinematographers (ASC), explored the question of the practical purpose of UHD-2 resolution – the equivalent of 8K – in televisions. The results of the study could not have been more different.

The structure of the study 8K vs 4K

In order to achieve the most meaningful result possible, the test setup had to be well planned and strictly regulated, of course. You can find all the conditions in detail on techhive.com. We have summarized them in short for you.

For simplicity, we also use the terms “8K” (actually 8192×4320) and “4K” (actually 4096×2160), although if you wanted to stay correct, it should actually be UHD (3840×2160) and UHD-2 (7680×4320). But since even the TV manufacturers use 4K and 8K, we’ll do the same in this article.

8k vs 4k double-blind study hardly any difference
The study shows hardly any differences in viewing perception.

General conditions

To find out how much added value the higher 8K resolution has, seven different clips, as different as possible, were played on an 88-inch 8K LG OLED Z9. These clips were all filmed in 8K (or better) or, in the case of the animated Pixar clips, rendered.

In order to have the perfect comparison material in 4K, these clips were then downscaled to 4K and then, so that there would be no switching times or the like, upscaled again to 8K. When upscaling, however, each pixel was merely expanded to 4 new pixels. So you then have quasi 4K material that is saved as 8K video.

The seven 8K clips being shown

Of course, each of the companies involved wanted to contribute something. That’s why there were two clips from “Dunkirk” by Warner Bros, one clip from “A Bug’s Life” and one from “Brave” (German: “Merida”) by Pixar, two clips from “The Tick” an Amazon Prime series and one clip of nature footage by Stacey Spears. All clips use the High Dynamic Range Codec, HDR 10 for short, and are very different in terms of the average and maximum brightness of the scenes.

8K vs 4K – Conducting the study

A total of 139 people took part in the study. Before the people saw the clips, their eyes were examined, so that one can also be sure that the results have content.

Brief digression: The Snellen eye test was performed to determine the visual acuity of the participants. The result is always given in the form 20/x. The average value is 20/20, which means that one sees just as sharply from 20 feet away as a person with normal vision sees from 20 feet away. 20/40 would mean that you see as sharp from 20 feet as a person with normal vision sees from 40 feet, i.e. you see worse. And 20/10 would mean you see as sharply from 20 feet as a person with normal vision sees from 10 feet, so you see better.

8k vs 4k Double-blind study Implementation
Interesting: Some of the test subjects even said they preferred the 4K material.

The majority (61%) had 20/20 or better. The respective test results are also taken into account later in the evaluation.

The test subjects then watched the clips in groups of five, with 2 people sitting 5 feet away from the TV and 3 people sitting 9 feet away. This corresponds to seating distances of 1.52m and 2.74m, respectively.

There were 3 runs in which all clips were shown 4 times each. Two runs always alternated between 4K and 8K resolution. Randomly, the different resolutions were given the letters “A” and “B”. In the third run, as a control group, only the 4K material was played, but it was also alternated with the letters “A” and “B”.

The subjects were then asked to indicate which material, “A” or “B”, was better after the runs. The possible answers were “much better”, “better”, “a little better” and the same.

Results of the double-blind study

The results of the study show that the 8K clips were only rated as “a very little bit better” on average. So most people did not notice any difference.

However, the results of the 8K vs 4K study were also dependent on the clips. The test subjects could see the biggest difference in the nature shots, although it is still very small.

Considering only the 61% of participants with at least average visual acuity, they described the 8K versions of “A Bug’s Life” and of the nature shots as slightly better than the entirety of the participants. But even these results are still very low.

Only when you evaluate those people who have a visual acuity of 20/10 and were sitting only 1.52 m away from the 88-inch OLED Panel do the results of the 8K vs 4K study become clearer. At least “A Bug’s Life” and the nature shots (who would have thought it?) could then be called really better. Our guide reveals the details of OLED, VA, IPS and other panel types.

Meaning of the results

8k vs 4k double-blind-study
TVs with 8K have four times the resolution of 4K.

Furthermore, the study shows additional discoveries. After all – apart from the close-ups – the most common result came down to a tie for all clips shown.

Even more surprising is that a quarter of all test subjects rated the native 4K material in comparison to the recordings in 8K as being better.

According to the person in charge, the reason for this is that a majority of the participants must have been guessing. If you want to learn more about 4K resolution, then take a look at our guide in the knowledge section.

8K vs 4K: Meaning of the study

The crucial question: What do we deduce from this? The simple answer is that most people should not buy an 8K TV because of the resolution. After all, the results only became clearer when people with above-average visual acuity sat just 1.52m away from an 88-inch TV. In relation to the small distance, the viewing angle in this case is a whopping 65°, which would be far too much for most viewers.

So is 8K dead?

No, 8K will continue to exist and the TV manufacturers will also bring more and more 8K TVs onto the market for an ever lower price. After all, that’s what marketing is for.

However, even in the future, most movies or series will not be produced in 8K resolution, at least not every step of the production chain. This means that it is important that 8K TVs also have a good 8K upscaling feature.

The really important result of the 8K vs 4K study, however, is that resolution is not the decisive factor when it comes to image quality. The other factors for a good picture are much more important. Thus, HDR is of much greater importance. In the same way, it is important that all the things we report about in the individual TVs are correct.

That means that the properties like contrast, brightness, color space coverage and so on are on a good level. The resolution is not the most important criterion. However, the right seating distance plays an important role. Our tvfindr TV size calculator tells you in detail what you have to pay attention to. The resolution is also not included in our direct comparison.

That’s not to say that an 8K TV is a bad choice, it’s just that resolution shouldn’t usually be the deciding factor. For example, if you’re looking for an 88-inch TV with truly impressive picture quality for home cinema, the LG OLED Z9 is an excellent choice, but for reasons other than resolution

Tobias

tvfindr Editorial

[email protected]

As a studied technology journalist Tobi likes to write regularly about the colorful world of TV sets & Co. Further interests: Music, cars, gaming, soccer