The HDTV revolution was the greatest thing that ever happened to the TV-making industry. Almost everybody finally had a reason to buy a new set, and sales skyrocketed. But once that transition period was over, sales began to drop, and the industry has been looking for a replacement ever since.
HDTV was the first major change in television tech since color TV in the 1960s. Getting everyone to replace their fancy flat-screen HDTVs again after just a few years has always seemed to me like a sucker's bet. But if you're a TV manufacturer, you've got to do something to keep the action! So a few years ago, CES was The One With All The 3D TVs. And very few consumers--the people who literally put the C in CES--cared.
There are still 3D sets at CES, but 3D has simply become irrelevant. The TV makers have moved on to the next new technology that they hope will spur a resurgence in TV sales.
This one's called Ultra HD, or 4K, and it threatens to make your HDTV look like the 16-inch Magnavox set I had growing up. (There's also 8K coming down the pike, which will make 4K look pedestrian, and presumably one day there will be 16K, which will make the real world look like a pencil sketch. But first things first.)
At first glance, 4K has a whole lot of advantages as a TV breakthrough when compared to 3D. You don't need to wear funny glasses to appreciate 4K, and watching it doesn't give you a headache. 4K is, quite simply, HD with even more pixels. While HDTVs are gorgeous and a vast improvement over the old standard-definition format, even an immaculate 1080p Blu-ray movie can't match the resolution of a film in a movie theater. But 4K resolution (essentially 2160p, or twice as many horizontal lines of resolution as current HD) is a lot closer to a 35mm print than current HD. (Some movie studios have scanned in films at 4K resolution for archival purposes, though it's inaccurate to say that 4K can match 35mm when it comes to resolution.)
Technology progresses forward, inevitably. I have no doubt that 1080p will eventually be supplanted by higher-resolution TV formats, just as high-resolution displays are appearing on all of our mobile devices and will soon be on all of our computers too. But I think that if TV manufacturers expect to sell a lot of 4K TVs in the next five years, they're kidding themselves.
The first hurdle is that people just don't upgrade their TVs as fast as they upgrade their phones and computers. We all just bought HD flat-screens--we're not all going to rush out and buy new TVs soon. But more than that, the upgrade from HD to Ultra HD just won't provide as clear a benefit to consumers as the upgrade from a big standard-definition tube set to a thin, high-def flat panel.
Some people can't tell the difference between HD and standard-definition--you would not believe how many people out there right now are tuning their high-def TVs to standard-definition channels without any knowledge of what they're doing. And that was a huge jump in quality. I'd wager that most people can't tell the difference between 720p and 1080p signals. So how many people are going to be able to notice the difference between 1080p and 2160p, and how many will care enough to make it worth upgrading their equipment? My guess is, not that many. (Note that I'm not saying there isn't a visible difference between 4K and standard HD. There very definitely is, and I saw it with my own eyes here at CES. I'm saying that I doubt there's enough of a difference to begin a mass consumer migration to 4K, especially at the asking prices for some of these sets.)
Then there are the bandwidth issues. High-definition video requires a pretty large data transfer. In the past, cable and satellite companies would often reduce resolution and crank up compression in order to fit HD channels through their pipes. It already takes a fast, beefy connection to stream a 1080p movie from iTunes. How much faster would that connection need to be if everyone was trying to watch 4K movies instead? Time marches on, and bandwidth will increase, but it's going to take a while.
Then there's the size issue. 4K resolution really only becomes visible on very large TVs, as people tend to sit several feet away from a TV when they watch it. So let's say you fit 2160 lines of resolution on a 40-inch TV set. By the time you sit down on your couch, you'll be so far away that the added resolution won't be visible. (This is the same calculation, involving distance and resolution, that goes into determining what "retina resolution" really means.)
If 4K pictures are only really noticeable on screens measuring 70 or 80 inches diagonally, how many people will ever want one? The average TV screen size keeps going up, but how many homes can fit such a gigantic screen? I remember a sci-fi story I read once, where TVs were replaced by a kind of wallpaper that was passive most of the time, but could transform an entire wall into a screen. If that wall comes in 4K, maybe things make more sense.
Finally, there are all of the ancillary bits of infrastructure that will need to be upgraded before 4K becomes common. Cable and satellite boxes will have to support 4K resolution. You'll need to buy a new 4K Blu-ray player and 4K Blu-rays to play on them--if they ever actually make such beasts. Or you'll just have to download 4K video files from new 4K video stores, which will need to obtain 4K versions of the same videos they currently offer in HD and SD formats. (Sony is actually bundling a server with its giant 84-inch TV that includes 10 movies in 4K resolution to entice people to dip their toes in the Ultra HD waters.)
I think 4K is cool. I think it's going to make it in the living room in a way that 3D never did. But will most of us have a shiny 4K TV in our homes in five years? I just can't see it. People have just bought TVs, think HDTV resolution looks pretty good, and don't necessarily have room for a big enough set to make 4K worth it.
For the rest of this decade, 4K seems doomed to be the province of home-theater nerds who are willing to spend a lot of money. That's not a bad thing--I say this as someone who bought an HDTV way before most people did, and I spent a lot of money for the privilege. But if the TV manufacturers are hoping to rekindle the massive HDTV sales of earlier this decade on the back of the 4K revolution, they're going to be disappointed.