UHD and the Law of Diminishing Returns

I suspect that most people are generally familiar with the concept of the Law of Diminishing Returns. There are formal definitions, of course, but for my purposes, let’s just say that it describes a dynamic in which additional investment in something yields less and less measurable benefit, and that you eventually reach a tipping point where it no longer makes sense. It has its basis in financial concerns, but it’s often applied more broadly, such as (in this case) technological improvement.

I may well be a tech curmudgeon, but I think we’re basically there with UHD (ultra high-definition) television.

This article was originally going to be one about the fact I’d finally broken-down and bought a “4k” (UHD) television*. It’s not that it was a conscious choice, mind you; we wanted a big screen TV for our large multi-purpose room in the basement so that using the spin bike located in that room didn’t mandate 30 to 60 minutes of extreme boredom. (All the new programming from our cord cutting was beckoning, basically.)

So off to Sam’s Club we went last month, and essentially, UHD displays are all they have. We ended-up with a nice 60″ Vizio UHD television for a measly $500. Cheap as chips, as the Brits say.

It necessitated another Amazon Fire TV Stick, so off to the Amazon store to pick-up a 4k version of one, and a short time later, we were beholding 4k UHD television in all its supposed glory.

To be sure, a 4k UHD source on a 4k UHD television offers a really nice viewing experience. Not that there are that many such sources without paying extra; Amazon Prime Video does have some content in 4k, but not much; at least it doesn’t cost extra. Netflix charges you more for it. And Hulu doesn’t offer it at all at the moment.

And that sort of brings me to the main point here: Have we hit that tipping point suggested by the Law of Diminishing Returns? It sort of seems like it.

Yes, as I said, a 4k UHD picture is great. Watching Amazon’s The Grand Tour in UHD is spectacular, even. But is it really a massively better experience in any material way than traditional 1080 HD? No, and as other tech outlets have also pointed-out, more pixels alone doesn’t necessarily deliver a better picture.

HDR (high dynamic range) matters; it delivers whiter whites and blacker blacks. WCG (wide color gamut) matters; it delivers truer, more accurate, more natural color. But when you add better dynamic range and better color to a 1080 HD display, you’re likely going to be impressed by the improvements as much (or even more so) than by adding more pixels.

There are two other factors as well. First is screen size. 4k UHD is primarily on larger screen televisions, while 1080 HD are on mid-size these days, and 720 HD on smaller ones. There’s a reason, and it correlates to viewing distance; the farther away from the screen you are, the less likely you’re going to notice any qualitative difference between the resolutions. Most of us are not watching a small screen television from two feet away (for example). And when you get to big screens, unless you’re up close, it’s the same story. (It’s the same reason why we do notice the qualitative difference with a “Retina” screen on our iPhones; we’re looking at it from inches away, where those extra pixels do make a noticeably sharper image.)

Researchers testing this in one study (referenced in this IEEE broadcast engineering article which also refers to the Law of Diminishing Returns, in fact) had viewers compare the quality of images on 56″ televisions when viewed at 9 feet from the screens. That distance is not regarded as optimal (it’s much farther away), but it’s nevertheless fairly typical in most home viewing environments. Comparing a native 4k UHD image, vs. upconverted 720p, 1080i and 1080p, there was less than 1/2 a point’s difference in perception between them.

In other words, the average user in the average viewing environment can’t really tell the difference in most cases. Indeed, my admiration of my new 4k UHD television was based on assessment about 2 or 3 feet away from the screen. When I’m on the spin bike clear across the room? Yeah, it’s a nice picture, but I’m not exactly bowled over by the difference between it, and the other big screen in the house.

This makes me wonder, honestly, what some of the television makers are thinking by introducing 8k televisions. Availability of programming aside, will anyone really be able to tell the difference? Or care? Or be willing to pay a premium for it? In time, perhaps, but if most of us can’t see much improvement from the move from 1080 to 4k UHD, who among us will truly be able to appreciate another doubling in pixel count?

That’s probably why Hulu isn’t even bothering (yet) with 4k content (let alone 8k content)… They understand that most of us just can’t tell the difference — and aren’t willing to pay the premium.


* It bugs me that I’m using the term “4k” here at all, because UHD isn’t actually 4k, technically speaking. But this shorthand persists, and I’m not going to fight it. Plus UHD is applied to 8k as well, since manufacturers love to make this as confusing as humanly possible.