Researchers from the University of Cambridge, working with Meta, have found that for the average living room setup, there is no visible advantage in shelling out for anything beyond 2K. Basically, your eyes can’t tell the difference.
University of Cambridge researcher Dr Maliha Ashraf said “At a certain viewing distance, it doesn’t matter how many pixels you add. It’s just, I suppose, wasteful because your eye can’t really detect it.”
The study, published in Nature Communications, set out to find the resolution limit of human vision. While 20/20 eyesight is often quoted as standard, Ashraf’s team noted most people with decent vision can spot finer detail than that.
“If you design or judge display resolution based only on 20/20 vision, you’ll underestimate what people can really see. That’s why we directly measured how many pixels people can actually distinguish,” Ashraf said.
The boffins ran tests using a 27-inch 4K display rigged to move towards or away from 18 volunteers. They showed them ultra-fine vertical lines in various colours and asked them to spot the pattern from a plain grey block. When the lines became too fine to see, the image just looked grey. This was the point at which human vision taps out.
The team found that people could resolve about 94 pixels per degree (PPD) on greyscale, 89 PPD on red and green patterns, and 53 PPD for yellow and violet.
In a separate test with text instead of lines, the results were similar. Participants were asked to judge when white-on-black or black-on-white text looked sharp compared to a reference.
Ashraf said the findings matched up and confirmed that after a certain resolution, more pixels don’t mean more clarity.
To make the point even clearer, the researchers released a resolution chart for common telly sizes and viewing distances. If your setup lands in the shaded region, a higher-resolution screen will offer absolutely no visual upgrade.
They also launched a free online calculator where users can punch in their screen size, resolution and viewing distance to see whether they’ve been duped by the pixel arms race.
“If someone already has a 4K, 44-inch TV and watches it from about 2.5 metres away, that’s already more detail than the eye can see. Upgrading to an 8K version of the same size wouldn’t look any sharper,” Ashraf said.