HD 101: 3D FAQ

By Ben Drawbaugh posted Apr 23rd 2010 12:59PM

Feature

While not everyone is sold on 3D at home yet -- or even in the theater -- most still have at least a few questions, and in the past year or so we've heard 'em all. So we figured we might as well share all the questions and the answers in one easy to read 3D FAQ. This is by no means comprehensive, but thanks to the wonders of the internet if we missed something it isn't too late to ask in the comments and watch in wonder as the post magically gets updated.

Why are there two display formats? Is this a format war?

No, it isn't a format war as both formats will display the same content. In active shutter glasses systems the glasses are more expensive where with circular polarized all the cost is in the display.

Are one brand of Active Shutter glasses compatible with all TVs?

No, shutter glasses aren't compatible but just like remotes, there are universal ones.

How are the Active Shutters glasses powered?

Some glasses have internal batteries and come with chargers, others use small watch-type batteries.

Do active shutter glasses work with different 3D content formats?

Yes, the glasses are specific to TV, not the source.

What are the different 3D content formats?

Just like HD has different resolutions, 3D has different formats. There is frame compatible that is backwards compatible with set-top boxes, then there is the new MVC AVC codec that requires new equipment but it does double the resolution. It is the left image plus the difference for the right.

Isn't frame compatible half the resolution of HD?

No, it's actually the exact same resolution as HD. Sure it would be better if the resolution was doubled, but it still isn't less resolution than HD.

Who's using what formats?

Broadcast mediums like satellite and cable are using frame compatible since it works with existing set-top boxes. Blu-ray is using MVC and requires a new Blu-ray player.

What resolution is 3D in?

Both 3D formats support 1080p and 720p. Blu-ray is 1080p 24 per eye or 720p 60 per eye. 3D broadcast is 1080i 30 per eye or 720p 60 per eye.

Is HDMI 1.4a required for 3D?

No, in fact many HDMI 1.3 cables, switches and other equipment will work with multiple 3D formats, but none are guaranteed to work. HDMI 1.4a equipment is guaranteed to work with most 3D formats.

So if I buy a new 3DTV, what else do I need to watch 3D via cable or satellite?

Since most existing set-tops support frame compatible 3D, you won't need anything else. But until your box gets a firmware update that'll make it 3D aware, you'll need to manually select the format.

How much bandwidth does 3D need?

Frame compatible 3D uses the same as HD, but DirecTV says it's more efficient to compress. 3D Blu-ray uses about 50 percent more throughput with a higher maximum bit rate of 60Mbps.

Who cares about 3D, I want 1080p at 60 fps.

We all do and in fact cable and satellite plan on delivering 1080p60 per eye eventually, but it'll require a new set-top box -- no word on which codec will be used, but you'll be able to watch it in 2D too.

Will a 3D channel require a full 6Mhz QAM channel?

No, not at all. Even the ultimate 1080p/60 per eye would easily fit into half a QAM channel. You see since the set-top needs upgraded anyways, it'll be upgraded to one that supports some variation of H.264, which is much more efficient than MPEG2 that's used today.

How will 24p 3D be displayed on a 240hz HDTV?

Sony 3DTVs display 24p 3D at 120hz per eye, so each frame will be shown 5 times.
Panasonic 3DTVs will display 24p 3D at 96hz per eye, so each frame will be shown 4 times.

Are there even any 3D channels?

Other than a few 3D specials there aren't any channels live yet, ESPN will launch its 3D channel this Summer on DirecTV -- no one else has announced carriage yet. DirecTV also plans to launch a few 3D channels this Summer including a PPV channel and a variety channel. All will use the frame compatible 3D format but will probably be different resolutions (ESPN is expected to be 720p60, might be some 1080p24 PPV movies too).

So... sports and movies, is that it?

No, Discovery and Sony are working to launch a 3D channel next year that might be called 3D.net.

When are we going to start seeing 3D Blu-ray Discs for sale?

No firm dates yet, but Blu-ray movies should start shipping this Summer, in the meantime demo material comes with Samsung and Panasonic's 3D kits.

Do 3DTVs cost a lot more than 2DTVs?

No, not really. In fact the first generation 3DTVs from Samsung and Panasonic are actually cheaper than their comparable-older 2D versions.

Older TVs can't be upgraded to play 3D. Even the latest 120Hz displays can't accept the signal and there's no IR emitter to sync the glasses.

Can I use the 3D glasses as sunglasses?

Well you can do whatever you want, but while the glasses do block light they don't really work as sunglasses.

If they block light, does that mean the TV is dimmer?

Kind of, displays actually automatically crank up the brightness to compensate for the dimming of the glasses, but not as much as they dim. The good news is that the glasses do improve the display's perceived black levels.

Can I upgrade the firmware in my Blu-ray player to support 3D?

Only the PS3 is getting an update, most older hardware can't be updated to support the new MVC version of AVC that is used to encode 3D.

Can I watch 2D on a 3DTV?

Yes of course, you don't have to watch 3D all the time. The newer HDTVs have better 2D performance as well and you can even watch 3D content in 2D if you want.

Can I watch this new 3D content on the 120Hz HDTV I just bought?

No, older TVs can't / won't be upgraded to be 3D compatible. Even the latest 120Hz displays can't accept the signal and there is no IR emitter to sync the glasses.

So what my Mitsubishi or Samsung DLP has been doing 3D for while, so can I just pick up a 3D Blu-ray player and enjoy?

Nope, DLPs use the checkerboard 3D format which needs a converter, but Mitsubishi does have one coming for an estimated $100. In addition some 3D Blu-ray players like the Panasonic 3DT-300 will output checkerboard 3D -- thanks snickering hound.

Can I watch 3D on my computer?

Yes, all you need is a display that'll accept 120hz input and an nVidia 3D vision kit. It comes with 3D playback software and there are updates for the Blu-ray PC software to make them 3D compatible.
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