> 720p is far from fantastic. It's noticeably blurry, even on mobile. 1080p is minimally acceptable, and is now over 10 years old.

Not OP. I would say these are far-fetched claims that need defending. Most blurriness of mobile video comes from the low bitrate it's encoded at. Basically nobody is watching Bluray quality 720p or 1080p materials on a phone - and that's the problem, not the resolution.

My guess is that a typical middle or even middle-upper class family is going to have a TV that is less than 70 inches, and is 10+ feet from most viewers. Even with 20-20 vision, the full quality provided by 1080p is not even visible at that distance! (You'd need to go all the way up to 78 inches at 10 feet, or sit 7 feet from your 55 inch set to even get the full benefit from a 1080p set.) See this very helpful chart: http://s3.carltonbale.com/resolution_chart.html

Most of the benefit in 4k video comes from recent advances in HDR presentation and better codecs, not from the resolution. Sure, if you're a real stickler for quality, you might be sitting 6 feet from your 80 inch OLED set, and 4k is definitely for you in that case, but it's really not that important to the average person. In my case, I can barely distinguish between 720p and 1080p on my set even with glasses on.

Now granted, it's great to have laptops and tablets at higher resolutions, because your face is smashed up against them and you're often trying to read fine text. But that's not the video case that's being talked about here.

I don't need to get the full benefit to care about the difference. And in my experience there's a lot of screens closer than 10 feet to couches.

On mobile, 720p starts to get shoddy once your screen hits 5 inches across.

So while 4k is situational, and encoding quality is more important than the extra resolution most of the time, 1080 vs. 720 is pretty clear-cut; 1080 should be considered the minimum for most content.

Note that I was talking about the full benefit of 1080p, not 4k. My points are that 4k is usually pointless, and therefore that 1080p is usually better than just "minimally acceptable", since most of the time we don't even get the full benefit of it.

> On mobile, 720p starts to get shoddy once your screen hits 5 inches across.

Even assuming you're right abut this, I guess I really just have a hard time caring. Anything you watch on your phone is at best something you don't give a shit about, artistically speaking, and it's hard to imagine 1080p vs 720p making any kind of difference to the experience. (I suppose I might be biased since my screen is "only" 5.2 inches diagonally - I get the smallest one I can whenever I buy a new phone.)

And for what it's worth, using the same math as for my previous comment, you can't even get the full benefit of 720p on a 5 inch diag screen unless you're holding it less than a foot from your face. Granted, you can get the full benefit of 1080p at a little under 8 inches, but I'm suffering even imagining trying to watch a video this way. Even at this distance, I would dispute using "shoddy" to describe how 720p will look.

The math is actually pretty simple: for a 720p screen, there are sqrt(12802 + 7202) pixels on the 5 inch diagonal, so a distance of 5 inches / sqrt(12802 + 7202) per pixel. 20/20 visual acuity can resolve roughly 1 arc minute, or pi/10800 radians. By the arc length formula, the distance we calculated subtends that angle at (5 inches / sqrt(19202+10802)) * (10800/pi), or 11.7 inches.

> And in my experience there's a lot of screens closer than 10 feet to couches.

Note that I addressed this point. If you have a pretty typical 50 inch TV, you've got to have it closer than 7 feet from your couch for 4k to make any difference at all.

> Note that I was talking about the full benefit of 1080p

Yes, so am I.

> therefore that 1080p is usually better than just "minimally acceptable", since most of the time we don't even get the full benefit of it.

If most of your users would be limited by 720p, and 1080p is standard and easy to do, then I'm comfortable calling 1080p the minimum.

> I'm suffering even imagining trying to watch a video this way.

The official "Retina" numbers have a phone 10 inches from your face. And that's about where I hold it when I have my glasses on.

> 20/20 visual acuity can resolve roughly 1 arc minute, or pi/10800 radians.

That's a good baseline number, but a lot of people can beat it by a significant fraction.

Average visual acuity for young people is about 0.7 arcminutes, best being around 0.5.

There seems to be disconnect about how people are consuming media. For me holding a 2280x1080 6.3" phone ~8" from my eyeballs is a natural viewing distance and I can see the full resolution without difficulty. And at least from my point of view a 65" TV is also a pretty typical size.

> That's a very bold claim. Have any studies or polls to back that up?

From 1:

> In Japan, only 14 percent of households will own a 4K TV in 2019 because most households already have relatively new TVs, IHS said.

Let's dissect the reasoning. Most households already have a relatively new TV, thus a low adoption rate. Implying that needing a new TV generally, not the desire to upgrade resolution, is the primary motivating factor in purchasing a TV. In fact, most 4K TVs are already as cheap as the rest of the market.

I truly believe that almost everyone does not care about 4K whatsoever. In fact, even if they do 'care' it's not because they know what they're talking about. Most of the enhancements that 4K TVs bring are an artifact of better display technology, rather than increased resolution. See 2.

Streaming 4K+ video is a waste of resources with no tangible benefit to anyone other than marketing purposes. Netflix streams '4K' because everyone has a '4K' TV now and they demand it.

[1]: https://www.twice.com/research/us-4k-tv-penetration-hit-35-2...

[2]: https://www.cnet.com/news/why-ultra-hd-4k-tvs-are-still-stup...

I agree with most of what you're saying, but this is actually wrong.

> Streaming 4K+ video is a waste of resources with no tangible benefit to anyone other than marketing purposes. Netflix streams '4K' because everyone has a '4K' TV now and they demand it.

It's not inherently wrong, just practically so. The difference is that Netflix (and often other streaming services) max out at a much higher bitrate for their 4k streaming, and are using a better codec (H.265) as well. By comparison, Netflix's bitrate for 1080p is severely limited and so if you compare the two, even watching at the 1080p level of detail, streaming in 4k will often be a vastly superior experience.

So it's not inherent (not a result of the resolution), but still, streaming 4k is not pointless at present.

Your first link includes an extra detail which is important:

> In addition, “with the Japanese consumer preference for smaller TV screens, it will be more difficult for 4K TV to expand its household penetration in the country"

With a smaller TV screen, yeah, you don't need 4K.

But in the USA, larger screens are desirable. And that's seen in the expected 34% 4K adoption rate in the USA your article describes.

I still use a 1080p TV, but it's also only 46" and is 10 years old. I'll probably be buying a 4K 70-75" OLED later this year.

My computer monitor is 1440p. I could have bought 4K when I upgraded, but I'm primarily a gamer and I wanted 144 hz, and 4K 144 hz monitors didn't exist yet.