You may already know by now, but new home theater projectors, and soon TVs, will be arriving sporting over-the-top resolution of 4K. Do you want it? Do you need it? What is 4K anyway?

4K is the shorthand term for an onscreen resolution of 4096 x 2160 pixels, which is about 4 times the number of the 1080p (1920 x 1080 pixels) TV you just bought.  Only a few companies right now offer consumer 4K projectors for home theater use, and there are no 4K TVs on the market, but I expect 4K to be one of the big messages coming out of the Consumer Electronic Show in January (several prototypes have been shown at conferences).

So why 4K? First, let’s be clear—the primary reason manufacturers come out with a new technology is so they can make you think the old technology isn’t good enough anymore. Then you run out and buy the new thing. (How many people have replaced their perfectly-good iPhone for a new iPhone?) Sometimes they’re absolutely right. When HDTV was introduced, standard television hadn’t seen a significant change in decades, so HD was exactly the revolution the industry said it was. Then came the 720p vs. 1080i vs. 1080p debates. When 1080p first emerged, many people argued it was unnecessary and impossible to discern. Depending on the TV, the seating distance and the content, some of those naysayers were right, though today a good Blu-ray on a good 50-inch or larger 1080p TV can’t be beat.

Will 4K TVs be an unnecessary upgrade that manufacturers will convince us we need? There are several good reasons why we don’t need 4K TVs. First, it will be nearly impossible to see. On a typical 50 to 60-inch TV, viewed from a typical sofa distance of 8 to 10 feet, the improvement will be minimal if noticeable at all. Maybe jagged edges on diagonals will be lessened, and text might look better, but quality TVs already look pretty damn amazing. Black level usually has a greater impact on a TV than resolution. It’s the black level that creates the depth and dimensionality, not the number of pixels. 

On bigger TVs such as 65, 70, 80, and 100-inch whoppers, maybe the increased resolution will be more obvious. The demos I’ve seen of 4K projectors at the 2011 CEDIA Expo were pretty amazing, but I’m talking about TVs here, not projectors with 120-inch screens.

So what’s the point? One of the biggest reasons I can see is for 3D, specifically 3D TVs using the Frame Pattern Retarder method and passive polarized glasses. LG is the biggest proponent of this variety of 3D TV, but Toshiba and Vizio also sell FPR passive 3D.

In passive 3D TVs, the 3D image is cut in half by the polarized glasses. This is one of the main arguments that companies like Samsung, Panasonic and Sony use to say their method of active shutter 3D TV is superior. The latter method preserves the full 3D 1080p resolution.

So what does 4K do for passive 3D? It solves the resolution problem. If the TV had double 1080p resolution onscreen, then when the glasses cut that in half (1080p to each eye) you’d still have full HD 3D without the problem of rechargeable glasses.

Sounds great right? But the tradeoff would at a be cost. A 4K TV is going to carry a premium price so the money you saved stuffing 3D glasses in your coat as you left the latest 3D movie would be more than eaten up by the extra cost of the TV. Possibly a lot extra.

Autostereoscopic TVs (glasses-free 3D) are also 4K in order to deliver 1080p 3D, but we’ve yet to see a retail launch of one. That may come early next year (fingers crossed), or it may not.

If you had a 4K TV what 4K content would you watch on it? At the moment, none. Blu-ray players can’t play 4K. Cable can’t even deliver 1080p, so 4K is out of the question. What about downloads or streaming? My money is on that in the long run, but it may be a very long run.

Without 4K content a 4K TV will just be upscaling all the lower resolution material—several home theater receivers already do that in a nod to future-proofing. It might do a very good job of that, but it can’t create picture detail where no picture information exists.

On the other hand, a 4K display will allow you to either sit closer to the TV or get a bigger TV than would have otherwise been recommended for your seating distance. If the pixels are smaller, and there are a lot more of them, you can get closer before they become discernible. 

Gaming might be an area that could greatly benefit from 4K—the added resolution would do a lot for fast, detail-heavy game graphics, and gamers are historically early adopters. Plus, the consoles are beginning to get a bit long in the tooth and due for an upgrade.

I look forward to attending CES in January and being proven completely wrong on all of this.

Grant Clauser - Technology and Web Editor, Electronic House

Grant Clauser has been covering home electronics for more than 10 years with editorial roles in several consumer and trade magazines. He's done ISF-level damage to hundreds of reviewed products and has had audio training from Home Acoustics Alliance and Sencore. He's also the author of the book The Trouble with Rivers. Follow him on Twitter @geclauser.