From sci-fi to sports, documentaries to kids' flicks, 3D is the next big thing for the world of home theater. HDTV may make your image look brilliant, but only 3D promises explosions that make you flinch and landscapes that seem to be rolling out of your TV.

If you bought an HDTV set early on, you probably remember the sting of having nothing to watch at first--and if you picked HD-DVD over Blu-ray, you may have had the sinking realization that your $300 player was becoming obsolete. Don't make those mistakes with 3D TV; just read through this 3D TV FAQ, and you'll have all the details you need before you start your holiday shopping early (or decide to wait).

How does 3D TV work?

All 3D displays work by showing each eye a slightly different image, which creates the illusion that you're seeing something from more than one angle. For example, the classic red-and-blue "anaglyph" 3D glasses achieved this effect by using the colored lenses to filter red light to one eye and blue light to the other.

The drawback of the anaglyph method, of course, is that it practically obliterates the color from the image. Instead of using a light filter, current 3D TVs work by combining a pair of powered glasses (called "active shutter glasses") with a television that has an infrared emitter. When the TV plays a 3D movie, it alternates between displaying an image for the left eye and displaying one for the right; its infrared emitter instructs your glasses when to dim the left lens and when to dim the right lens to create the illusion of 3D.

This method is significantly different from the one used in movie theaters, by the way. Most 3D movies use glasses that are polarized (kind of like sunglasses) differently in the left and right lens; a special filter fitted to the movie projector allows it to switch rapidly between images for your left eye and images for your right. In principle, it's similar to the red-and-blue 3D system, except that it keeps the color intact (though the polarization does dim the image a bit).

In any case, if you forgot to return your movie glasses after watching Avatar, you won't be able to use them with a 3D TV, since it uses a completely different display technology. For more information about how 3D TV works, check out our "Geek 101: Getting Behind the Scenes With 3D HDTV" post.

What equipment do I need to be able to watch 3D content at home?

You'll need a 3D-capable HDTV, a pair of 3D glasses, and (if you want to watch 3D Blu-ray movies) a special Blu-ray player; unfortunately, your existing Blu-ray won't quite cut it. For PlayStation 3 owners, Sony released a firmware upgrade in June to support 3D games, and the company is promising to provide a similar upgrade for 3D Blu-ray support in September.

As of now, it doesn't look as though you'll need to buy new HDMI cables or anything like that, so you don't have to donate your paycheck to Best Buy quite yet.

How can I tell whether my TV can display 3D images?

So far, only a handful of TVs from the big manufacturers can display 3D images: Samsung has a few higher-end LED-backlit LCDs (7000/8000/9000 series), plasmas (7000, 8000), and LCD TVs (750) that can handle 3D; other qualifying sets include Sony's Bravia XBR-LX900 series, LG's LX6500 and LX9500 televisions, and Panasonic's Viera VT25 line.

In other words, it's highly unlikely that you purchased a 3D-capable HDTV and didn't realize it. If you're still wondering whether your TV can show 3D images, just look it up on the manufacturer's Website--vendors aren't shy about promoting this capability on the relevant product page when they can.

LG, Panasonic, Samsung, and Sony are the only big-name TV manufacturers with entries in the 3D arena already, though models from Philips, Sharp, and Toshiba should reach the market in the next year or so.

My HDTV says that it's "3D-Ready." What does that mean?

A few manufacturers have sold TVs labeled as "3D-Ready." Many of the models in Mitsubishi's DLP HDTV line carry this designation, for example, as do a handful of Sony Bravia TVs. While the definition of "3D-Ready" varies from manufacturer to manufacturer, the term typically means that the set can display 3D content but lacks the IR emitter needed to sync the TV's image to the glasses--so you'll need to buy that separately. Also, because the 3D techniques found in DLP TVs ("Wobulating") sacrifice detail for a 3D image, if your source media is in 1080p ("Full HD"), it'll show in 3D at half that resolution.

How much does a 3D TV cost?

The total cost of fully 3D-ifying your home-theater setup depends on such factors as the set's display size and other features. Generally speaking, however, you're looking at investing at least $2000 in the set itself, plus anywhere from $220 to $400 for a 3D Blu-ray player and $150 for each additional pair of active shutter glasses (some sets will come bundled with one or two pairs).

What kind of content can I watch in 3D?

At this writing, not much 3D content is out there. After you've spent a bunch of money on a 3D setup, you might very well find that you can't watch anything in 3D quite yet.

So far, few 3D Blu-ray movies are available (Amazon.com lists only Cloudy With a Chance of Meatballs and Monsters vs. Aliens, and the latter is available exclusively as part of a $350 Samsung 3D starter kit).

Sports fans will want to catch ESPN's 3D channel, which is available on DirecTV, Comcast, and AT&T U-Verse (for an extra $10/month). But 3D is available only for specific events; check the channel's rather sparse 3D schedule to see what's on.

Aside from Blu-ray and ESPN 3D content, your TV provider largely dictates your content options; DirecTV subscribers have received a software update that added four 3D channels (ESPN 3D, a demo channel, a 3D movie channel, and a video-on-demand channel), Comcast currently has ESPN 3D plus a 3D channel limited to specific 3D events, and AT&T U-Verse appears not to have anything besides ESPN 3D.

3D gaming has begun to emerge, too. In addition to the PS3 firmware upgrade mentioned earlier, PC gaming has supported 3D for a year and a half now via kits such as the nVidia GeForce 3D Vision, which you can pair with a compatible 3D display to run plenty of games in 3D. Wondering if your favorite titles will work in 3D? Check out nVidia's recommended 3D game list.

Can everyone see 3D images?

Regrettably, not everyone can see 3D; somewhere between 4 and 10 percent of people simply can't see 3D images, though apparently the appropriate kind of stereoscopic vision can be "learned." Meanwhile, the disclaimers attached to 3D TV and theater displays are quite interesting. To judge from them, 3D TV isn't for the young, drunk, elderly, or pregnant, and watching it can actually cause disorientation, so you might want to hold off on buying a set until its precise effects are better known.

Can I watch regular 2D content on a 3D TV?

Yes, you can watch normal 2D shows on a 3D TV. (If you smirked to yourself while reading this, just remember that your friends and family will probably start asking you the same question during the holiday shopping season.)

Some 3D apps and devices offer support for upconverting a 2D source to 3D, though at this point such support comes mostly from Samsung's TV and Blu-ray lineup. The latest release of Cyberlink PowerDVD can upconvert to 3D with passable results, too. The upconverting modes probably won't make you want to rewatch your entire Blu-ray collection, but it's a promising start.

Do I need to wear those dorky glasses?

Yes--for now, at least. A number of companies are working on no-glasses 3D, or "auto-stereoscopic" displays, most of which use a lenticular lens system that displays a different image depending on where you're standing in relation to the display (if you've ever seen a movie poster that shifted as you walked by, it's the same idea). For the time being, however, it's substantially more expensive: A Chinese company named TCL sells a 42-inch display for about $20,000. Samsung is working on a lenticular lens display, too, though it's designed for commercial use (think flashy signs and such).

A mysterious Amazon.com preorder posting for a $6000 no-glasses 3D display (with built-in 500GB hard drive and Blu-ray player, no less) made waves a few months ago, but until "StreamTV" (not to be confused with Mitsubishi's StreamTV) has some images and a Website, don't start holding your breath.

Will my 3D glasses fit over my corrective glasses?

Yep. All 3D glasses are designed to fit comfortably over corrective glasses, though you'll want to try a pair on before you buy them. Unfortunately, nothing is available on the market at the moment to make you feel like less of a doofus for wearing glasses over your glasses.

Will my glasses work on all 3D TVs?

Not quite. In the rush to hit the market with 3D displays, manufacturers never paused to hammer out a design standard for active-shutter glasses, meaning that your Panasonic glasses won't work with your friend's Sony TV.

A few solutions may be in the works, though. XpanD offers universal 3D active-shutter glasses that can determine the type of TV you're using based on its IR signal and adapt accordingly. We haven't tried them out yet, but the company claims that they work with most of the 3D displays on the market.

In the meantime, you can use your Samsung glasses with Panasonic sets (and vice versa)--but only if you wear the mismatched glasses upside-down.