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Why 4K Still Doesn't Matter in Your Home

As 2013 begins to wind to a close, I thought I would bring up an old topic. Should (will?) 4K be embraced within the home? Here's a snippet from Geoffrey Morrison's article from 2012 on Why 4K TVs are stupid:

Most people sit about 10 feet from their television. At 10 feet (120 inches), your eye can resolve an object 0.035 inch wide, if like I said above, there's enough difference between it and the background (or its adjacent pixel, in this case). The memories of the Westwood school system that told me I was bad at math compels me to show my work, so feel free to check my math:

2 x pi x 120": 753.98" (circumference of a circle, with you at the center)
753.98 / 360: 2.0944" (360 degrees in a circle)
2.0944 / 60: 0.0349" (60 minutes in a degree)

This math, or just looking at your TV, tells you that you can't see individual pixels. What's interesting is that a 720p, 50-inch TV has pixels roughly 0.034 inch wide. As in, at a distance of 10 feet, even 720p TVs have pixels too small for your eye to see.

That's right, at 10 feet, your eye can't resolve the difference between otherwise identical 1080p and 720p televisions. Extrapolating this out, you'd have to get a TV at least 77 inches diagonal before you'd start having a pixel visibility problem with 1080p.

Or, you can move closer. Beyond being a math exercise, let's be realistic. No one's going to sit 6 feet from a big TV. I'd doubt 7 feet, either. So if we say 8 feet (96 inches), or 0.028 inch on the resolution side, this means you'd need a TV that's bigger than 60 inches to really benefit from 1080p.

In bringing the point directly to your home Morrison states:

So if your eye can't tell the difference between 720p and 1080p on nearly all modern televisions, what's the need for 4K?

Excellent question. There isn't one. Not as far as TVs go, anyway. You'd need a 2,160p TV over 154 inches diagonal before you'd be able to see the pixels. On a 4K 50-inch TV, the pixels would be roughly 0.011 inch wide.

Where's the crossover where 1080p and 4K become noticeable? It's not exact because of all the above mentioned variables, but suffice it to say at 10 feet, it's somewhere well above 77 inches.

Stu Maschwitz, a year later in 2013, echoes Morrison's article as he debates for himself 4K in the home:

Morrison goes on to back up this assertion with wonderful facts and math. If you bought a 60” television, you’d have to sit about four feet away from it before you’d perceive the full benefit of 4K over good old 1080p.

Like Stu says, read Morrison's article. Every word. It's smart, mathematical, and well reasoned. Now that may not stop 4K from taking over, but it should make you seriously question if you need it in your home theater setup.

And in an attempt to resolve the debate about if people can perceive the resolution difference from a normal viewing distance Richer Sounds in Leicester, England is conducting a 4K vs. 1080p viewing yesterday, Sunday, December 1.

Attendees will be invited to guess which TV is the 4K Ultra HD one, taking as long as they need to scrutinise the content from 9 feet away (and hopefully without asking the next person). By submitting their pick on a short survey form, participants will be entered into a prize draw. When both TVs are revealed towards the end of the event, those who have correctly chosen the 4K set will stand a chance to win £100 worth of Richer Sounds voucher.

My guess: the math holds and people at the Richer event will be simply guessing 50-50 on which is 4K and which is 1080p. Though there is the real possibility that a down sampled 1080p image from 4K will appear slightly sharper and therefore, better to the average viewer. We'll find out soon enough...