3D TV FAQ
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3D TV basics
Putting together a 3D TV system
Watching 3D TV
3D TV basics
Different 3D TV manufacturers take slightly different approaches, and there are "active" and "passive" models to choose from (see next question). But the basic idea at work in all 3D TVs is creating "left" and "right" versions of an image on screen. The tricky thing is getting the correct version of the image to the correct eye. That's where the 3D glasses come in.
All current 3D TVs require each viewer to wear compatible glasses in order to be able to see the 3D effects. As of August 2011, most 3D TVs use battery-powered "active" glasses. The lenses alternately block out the left or right images in sync with your TV. Only your right eye sees the right image and only your left eye sees the left image. Active glasses are much more sophisticated than the ones you get at the movie theater, which is why they cost a lot more. "Passive" glasses create separate right and left images in a different, simpler way.
Whether the 3D technology is active or passive, your brain combines the right and left images into one seamless whole, just like it does every day with the slightly different views you get with your right and left eyes. The end result is that most people are able to see a 3D picture.
Q: What's the difference between "active" and "passive" 3D TVs?
A: The first wave of 3D TVs released in 2010 were all active 3D TVs that used shutter-type active 3D glasses. In 2011, most 3D TVs are still active, but some TV makers have also introduced passive 3D models.
Active 3D — Active 3D TVs require viewers to wear battery-powered active shutter glasses to see the 3D effects. These shutter glasses feature LCD lenses that alternately block the view of the right eye and left eye in response to sync signals beamed wirelessly from the TV. Active 3D TVs provide full 1080p picture resolution for each eye. However, the glasses are expensive and usually bulkier than passive glasses, and some viewers are bothered by their high-speed flickering.
Passive 3D — Passive 3D TVs provide a 3D experience that's very similar to watching a 3D movie in a theater. For passive 3D TVs, the screen is doing almost all of the work. Not only are two video images being displayed, but there's also a special screen coating that works with the polarizing passive glasses to create the 3D effect. Passive 3D glasses are lightweight and inexpensive and require no batteries — they're virtually identical to the 3D glasses handed out in movie theaters. Passive 3D provides a picture that's crisp and bright and free of any traces of flicker. Passive 3D technology is less sensitive to a viewer's viewing angle or head movement, which makes it easier for several people to enjoy convincing 3D effects.
Q: Should I buy a 3D TV?
A: If you like the way 3D movies look at the theater and want that experience at home, then you'll probably like 3D TV. And while the selection of available 3D movies is still limited, Hollywood is releasing more titles all the time. See our question about what you can watch in 3D for more info.
You should also consider a 3D model if you're interested in getting top-of-the-line picture quality with your 2D movies and TV shows too. Since displaying 3D video requires a sophisticated, very fast, very responsive TV screen, 3D TVs boast some of the best 2D pictures out there.
Q: If I get a 3D TV, do I need a separate TV for regular 2D viewing?
A: Nope. Everything you watch on your regular TV you can also watch on a 3D TV. This might come as a pleasant surprise if you thought you could only watch the limited amount of 3D material that's been released so far. When you watch regular 2D video on a 3D TV, you won't have to wear 3D glasses and you won't see 3D effects. But you will see a superb picture because 3D screens are more technologically advanced, and produce the best-looking 2D pictures currently available.
Want to watch 3D TV? You need to wear a pair of 3D glasses that are compatible with your 3D set.
Q: Why do I have to wear glasses to watch 3D?
A: Glasses are a key part of how 3D TV works. A 3D TV alternates between "left eye" and "right eye" versions of an image very, very quickly. Whether your 3D TV is active or passive, the glasses ensure that the correct eye sees the correct image at all times. If you try watching a 3D program without 3D glasses, the image will look blurry.
TV makers are working on "glasses-free" 3D TVs, but the general consensus is that they're several years away from being ready for the market.
Q: Do all manufacturers use the same 3D technology?
A: Actually, there are some differences worth knowing about. First, be sure you understand the difference between active and passive 3D TV. Both types can provide a great-looking 3D picture, but one or the other might better suit your viewing preferences. Once you've decided on either active or passive 3D, there are still some other technological differences, like in the way different brands of active 3D TVs communicate with the 3D glasses. That's why you should double-check when buying 3D glasses that they're compatible with your 3D TV — often, that'll mean choosing glasses from the same brand.
Q: What's the resolution of 3D video?
A: That depends on both the video source and the TV. A 3D Blu-ray movie played on a 3D Blu-ray player is the highest-resolution source to feed a 3D TV: there are actually two video streams, each with full 1920 x 1080-pixel resolution. That ensures that both your right and left eye will see a full 1080p high-def image.
3D video from cable and satellite channels reduces resolution by half in order to fit the information into a single standard channel. Resolution is typically 960 x 1080 pixels, which means each eye sees a 540p image. It'll look good, but won't look as crisp as 3D video from Blu-ray.
Q: How is 3D TV different from 3D at the movies?
A: If you've seen a recent 3D movie in a theater, you probably wore the free glasses that were provided. These passive glasses have polarized lenses — they look a lot like standard sunglasses. These glasses are virtually identical to the polarized glasses that are used with passive 3D TVs, so watching a passive 3D TV is very similar to the 3D movie experience in a theater.
Active 3D TVs that use battery-powered shutter glasses can also provide an immersive 3D experience. The shutter glasses cycle 120 times per second to alternately block out the left or right lens in coordination with the video frames flashing on the TV screen. Some people are aware of a slight flickering sensation which can be distracting.
Putting together a 3D TV system
You'll need more than just a 3D TV to enjoy 3D at home — you'll also need glasses for each viewer, a 3D video source, and HDMI cables to connect your 3D gear.
Q: What do I need to watch 3D TV?
A: There are a few key pieces — see our question on how 3D TV works for more details.
A TV screen designed for 3D: You can choose from plasma, LCD, and LED-LCD models.
3D glasses for each viewer: Anyone watching a 3D TV needs to be wearing 3D glasses to see the three-dimensional effect. Make sure the ones you choose are compatible with your brand of 3D TV. To anyone not wearing glasses, a 3D TV picture will look blurry and distorted.
A 3D video source: A true 3D experience begins by feeding your TV a 3D video signal. The best example is a 3D-capable Blu-ray player playing a 3D movie. Most 3D TVs can turn a 2D signal into 3D, but it won't look as convincing.
HDMI cables to connect your 3D gear: HDMI is the only cable type that can carry 3D video. Most recent HDMI cables should be up to the job, especially if they're 2 meters or less in length. If you're buying new cables, look for ones labeled "high-speed," "1.3," or "1.4" to be sure. Check out our article about HDMI and our introduction to 3D TV for more info.
Finally, though it's not strictly necessary to watch 3D, you should also consider a 3D-capable home theater receiver. Check out our question about 3D receivers for more info.
If you plan on switching your 3D video sources through your receiver, you'll need one capable of passing those 3D video signals on to your TV. These days, virtually all home theater receivers are 3D-capable.
Q: I've got a home theater receiver that can't pass 3D video signals. Do I need to get a new one if I want to upgrade to a 3D system?
A: Strictly speaking, a 3D-capable home theater receiver isn't essential to a 3D TV system (see our question on putting together a 3D system for what is). But if you plan on switching your 3D video sources through your receiver, you'll need one capable of passing those 3D video signals on to your TV.
Now, if you don't have a 3D-capable receiver, you could run 3D video signals directly to your TV via HDMI, and run an optical or coaxial digital audio cable to your receiver for surround sound. That's a less-than-ideal solution though.
Having a 3D-capable receiver in your 3D TV system gives you a couple of key benefits. First, you'll still be able to take advantage of your receiver's HDMI switching, and just run a single HDMI cable to your TV (as opposed to running a separate one from your Blu-ray player). Second, you'll still be able to get the ultra-high-resolution soundtracks available on Blu-ray discs, like Dolby® TrueHD and DTS-HD™. (Those formats require an HDMI connection, so optical or coaxial digital won't cut it.)
Check out our article about setting up your receiver for more info on video connections and HDMI switching. And for more info on Blu-ray player connections, see our article about hooking up your Blu-ray player.
Q: Do my 3D TV and 3D Blu-ray player need to be from the same manufacturer?
A: No. Any 3D-capable Blu-ray player should be able to play with any 2010 or newer 3D-ready or 3D-capable TV. (One exception: if you bought one of the early 3D-ready Mitsubishi DLP models in 2008-2009, you'll need to buy a special converter box to make your set work with current 3D technology.)
Q: Do I need a special HDMI cable for 3D TV?
A: You'll need HDMI cables to connect all your 3D gear, since HDMI is the only cable capable of carrying 3D video. Most recent, good-quality HDMI cables should be up to the job, especially if they're 2 meters or less in length. If you're buying new cables, look for ones labeled "high-speed," "1.3," or "1.4" to be sure. Check out our article about HDMI and our introduction to 3D TV for more info.
Watching 3D TV
Blu-ray players that can play 3D Blu-ray discs are very reasonably priced and provide some added future-proofing.
Q: What will I be able to watch in 3D?
A: More and more 3D Blu-ray movies are being released. And check with your cable or satellite TV provider for details on which 3D channels are available in your area.
Also, most 3D TVs can upconvert 2D video to 3D. Of course, this won't look as convincing as true 3D — that is, movies and TV shows originally shot in 3D — but it will let you enjoy your TV's 3D capabilities more often. 2D-to-3D conversions adds a nice sense of picture depth, but you won't see objects coming out of the screen at you like you sometimes will with true 3D material.
Q: I've heard about 3D TV channels. Will I need special equipment from my cable or satellite provider?
A: From what we've heard, no, at least for now. Because of the way cable and satellite providers are breaking up the 3D signal (two 540p images, instead of the two 1080p images you get from Blu-ray) their existing equipment will be able to handle it. Should they upgrade to higher-resolution 3D channels in the future, you'll likely need new set-top boxes.
Q: Do I have to sit right in front of my 3D TV to get the 3D effect?
A: No. While you shouldn't expect to watch 3D video from the kitchen while you're making dinner, you should be able to get the 3D effect even if you're sitting off to the side.
Q: Can I use the 3D glasses from the movie theater to watch 3D TV?
A: That depends on what kind of 3D TV you have. The passive movie theater glasses will work just fine with passive 3D TVs from brands like LG and Vizio. But most of the 3D TV models currently available are active 3D, which means they require battery-powered "active shutter" glasses.
Q: Can I play a 3D Blu-ray movie on a regular Blu-ray player?
A: Yes. However you will only be able to play it back in 2D mode. 3D mode is only available when using a Blu-ray player that supports 3D content.
Q: When I try to play my 3D Blu-ray movie, my TV's screen goes blank. What's wrong?
A: The problem is likely that one of the components in your system doesn't support 3D video. For example, if you try to play a 3D Blu-ray movie on a TV that can't display 3D, the TV won't know what to do with the signal and the screen will be blank.
The same thing can happen if you're routing your 3D Blu-ray player's video signal through a non-3D home theater receiver. The receiver won't be able to pass 3D video on to your TV, resulting in an empty screen.
Many 3D Blu-ray players require you to choose between 3D and 2D viewing when you load a Blu-ray disc. If you choose 3D, the player switches to 3D mode, and you have a short amount of time to confirm your selection. If you don't confirm, the player assumes you might not be able to see the image, and reverts back to 2D.
Q: When I try to watch a regular 2D movie, my 3D TV's screen goes blank. What's wrong?
A: If your TV's set to display video in 3D only, it may not be able to accept a regular 2D signal. Go into your TV's display menus and select "Auto" (or something similar) — that tells the TV to display any incoming signals, 2D or 3D, rather than only 3D.
Q: I feel nauseated or dizzy when I watch 3D TV. Am I doing something wrong?
A: Short answer: no. Some people may have those kinds of reactions when watching an active 3D TV with shutter glasses, at least initially. One trick that's worked for some folks here at Crutchfield: don't try to focus on the background, just watch the main action in the foreground.
Q: I'm wearing the right 3D glasses, but I'm still not seeing a 3D picture. What's wrong?
A: If the glasses are the active shutter type, first make sure they're turned on — there's usually a power button somewhere on the frames although some of the latest glasses switch on automatically when picked up. If they won't turn on, then the battery may need to be recharged or replaced.
If the glasses are powered on and you're still not seeing a 3D picture, double-check that your 3D TV and 3D video source are both in 3D mode.
If that still doesn't do it, you may be one of the 5-10% of people who can't see the 3D effect in 3D video.
Q: My cable/satellite provider offers 3D channels, but I can't see them on my TV. What's wrong?
A: First, be sure that you've connected the box to your TV via HDMI — it's the only type of cable that can carry 3D video signals.
Next, check that both your cable box and 3D TV are in 3D viewing mode. Most new cable boxes will already come with 3D enabled. If yours wasn't installed very recently, you may need to turn it on manually. Depending on your cable box, you may need to manually switch back to 2D mode for 2D viewing, though some newer models can handle this automatically.
Your 3D TV will likely come with the 3D mode turned on. As you can see in our question above, you may want to set it to "Auto" to allow both 2D and 3D viewing; this mode should also work with your cable box.
Finally, you may want to contact your cable provider and double-check that the 3D channels are part of your programming package. They may not necessarily be included with what you currently subscribe to. And if our troubleshooting tips haven't helped, hopefully they can get you up and running.