The Digital Bits presents... A Guide to 3D for Everyone

RealD, 3DTV, Blu-ray 3D, active shutter glasses - these are terms you've probably heard mentioned on TV and in trips to Best Buy and other retailers. Certainly, anyone who's gone to a movie in theatres in recent months has heard about (or experienced) 3D on the big screen, with such hit films as Avatar, Toy Story 3 and How to Train Your Dragon. There's little doubt that 3D is here, and here to stay. What's more, the technology has finally arrived for you to enjoy the 3D experience in your living room. But what does it all mean? How does it work, and what special equipment do you need to give it a try?

As always, your friends at The Digital Bits are here to explain it all to you in simple terms. So let's get started...

RealD logo

3D: Active vs Passive

Right now, whether you're viewing 3D in a movie theatre or in the home, doing so requires those funny glasses. But not the silly red/blue (anaglyph) cardboard glasses of old. No sir, the glasses today are decidedly more high-tech. There are two main types of 3D display technology: Passive and Active. In both cases, glasses are used that are matched to the display or projection format. These are generally designed to be worn just like normal glasses, and in fact can be worn over the prescription glasses you may already use.

Passive (or Polarized) is the 3D process that's by far the most common in theatres - think RealD and IMAX 3D. You may be surprised to know that the process actually dates back to the early days of 3D cinema, but is now undergoing something of a high-tech revival. RealD and IMAX 3D each uses slightly different variations on the passive process, but all take advantage of polarized lenses. In a nutshell, the way the process works in theatres is that two different images - one for your left eye and one for your right eye - are projected at the same time on the screen but through special polarized filters oriented at right angles to each other. The glasses in turn each have matching polarized filters - the left lens matches the left-eye projected polarized image, and the right lens matches the right-eye projected polarized image. This allows each of your eyes to receive its own discrete image, slightly offset from one another, and your brain interprets the resulting visual input as 3D. It's tough to use this process at home, however, because the polarized lenses in the glasses reduce the amount of light in the image by as much as 30-40%. So the display or projection has to be that much brighter to compensate - something that's much easier to achieve in a theatre, where the lighting in the room is carefully controlled.

Active (sometimes called Active Shutter, or alternate-frame sequencing) is the 3D process that's most common in homes with new 3DTV displays. The advantage of active shutter for the home is that it can deliver a full 1080p image to each eye. The way it works is that the lenses of active shutter glasses are essentially mini LCD screens. When a small electric current is applied to them (via battery power), the lens goes dark (the shutter "closes"). This process is synched to the high-definition 3DTV display via an infrared or RF transmitter. The 3DTV alternately displays left-eye and right-eye 1080p images at high-frequency - some 120 times per second. When the left-eye image appears on the display, the left lens of the glasses is clear or "open" and the right lens is "closed" or dark, so only your left eye sees the image. Conversely, when the right-eye image appears on the display, the left lens of your glasses goes dark and the right lens is open, so only your right eye sees the image. This happens so fast that your brain shouldn't even notice the process - all you simply see is a great 3D presentation.

One exception: I should note that the Dolby 3D process currently being used in some theatres is actually a completely different process than either active or passive. In fact, it's based on the old anaglyph (red/blue) process, in that the digital projector uses slightly different color filters - and glasses with corresponding color filters in the lenses - to direct discrete left/right images to each eye. There's always an exception!

To be fair, some people have difficulty viewing 3D no matter what the display format used. Some estimates indicate that as many as 1 in 10 people can't properly process 3D images due to visual impairment, though this problem can often be treated with special prescription lenses or vision therapy. For others, the 3D effect can be so pronounced and intense that the sheer act of watching a full-length film can induce eye strain and cause headaches. In the home, reflections on the display screen can also cause similar problems. Still, when properly set-up and functioning, most people can and do enjoy the 3D effect that active and passive presentations provide.

3DTVs in the Home

Right now, you can buy lots of different high-definition 3DTV models for home use, from such manufacturers as Panasonic, Sony, Samsung, LG, Mitsubishi, Philips, Vizio and Toshiba. Generally, they'll cost between $200 and $500 more than regular 2D HDTV displays, depending on the size of the screen. Nearly all of these utilize the active shutter display process. (It's worth noting that several current models of Samsung and Mitsubishi 120Hz DLP HDTVs can up "upgraded" to full 3D compatibility via firmware updates and/or 3D accessory kits.)

You can purchase displays that come with everything you need, including at least one pair of active shutter glasses and the IR or RF transmitter (needed to sync the glasses with the display - this can be an add-on device or it may be built into the display itself), or you can purchase 3D-ready displays that don't include the glasses and transmitter. If you choose the latter option, when you're ready for the full 3D experience at some point in the future you can buy the transmitter and glasses separately as an accessory. You can also purchase additional pairs of glasses if needed. Note that there's no industry-standard "3D logo" used to identify all 3DTV displays - each manufacturer has their own way of branding their 3D-compatible models. So just ask your in-store sales person to be sure you're getting the right display.

Once you have a 3DTV, the transmitter and the glasses, you'll need 3D content to watch on it. This can come from a Blu-ray 3D player, a 3D signal via your broadcast, cable or satellite provider, or a 3D-compatible game system (currently the Sony PlayStation 3 is the only option). Read on (below) for more information on each of those choices. SOME (but not all) 3DTVs offer an option to convert 2D video signals to simulated 3D in real-time, but the process is far from perfect and looks nowhere near as good as content natively-shot in 3D format.

Currently, there are 1.8 million 3D HDTVs in homes in the U.S., compared to 39.3 million regular HDTVs. By 2015, the market analysis firm Futuresource Consulting expects there to be some 27.1 million 3D HDTVs in the U.S. compared to 45.3 million regular HDTVs.

For those of you with more elaborate, front-projection home theatre systems, Sony and LG have each already released 3D-compatible projector models (using the passive process), with a few more due from JVC before the end of the year. Additional 3D-compatible projectors are likely to be announced (by various manufacturers) at CES in January for release in 2011. They're currently more expensive than standard models (in the "$3,000 and up" range), but prices should drop in the months ahead.

A few things to note about the required active shutter glasses: More rugged, third-party models are starting to become available, but many of the glasses from the major manufacturers are a bit fragile, so you want to be careful when handling them - especially when letting your kids use them. They're also rather expensive at the moment, with prices running between $70 and $150 a pair (though that's expected to drop dramatically in the next year or so). The glasses are also powered by batteries - either you can swap the batteries out as needed or you have to plug the glasses into a standard outlet (via a transformer) to charge them. It's a good idea to make sure they're fully charged before you start viewing a movie, as a low charge will result in poor sync with your display and a poor 3D viewing experience rife with eye strain and headaches. Note that a fresh battery (or a full charge) is generally good for about 20 movies, and the glasses usually have low battery indicator lights to alert you.

One additional note about 3D viewing in the home: It's important to carefully control the light in your viewing environment when watching 3D displays, because unwanted light can cause reflections on the screen or interfere with the sync of the display and your glasses. Either can result in a poor 3D viewing experience.

Blu-ray 3D

Blu-ray 3D is not so much a new format, as it is an extension or "added feature" of the existing Blu-ray format. (In much the same way that DTS became an added audio option on DVD players a decade ago.) Essentially, the Blu-ray 3D discs have encoded on them a second, synched video stream for a total of two - one for each eye. The good news is that it doesn't matter what process your 3DTV and glasses use - active or passive. As long as you have a Blu-ray 3D-compatible player, any 3DTV (with glasses) should be able to display the content properly. Compatible Blu-ray 3D players and movie titles will feature this logo...

Blu-ray 3D logo

Blu-ray 3D functionality currently adds about $50 to the cost of a Blu-ray player, but that will drop over time so that 3D will simply become a standard feature of all Blu-ray players in the near future. Some 20 models of Blu-ray 3D player are now available - some for as low as $199 - with more due at CES early next year. The expectation is that by the end of 2011, anyone buying a new, affordable Blu-ray player model will have a hard time finding one that doesn't have 3D capability. To give you a sense of where this is going, the Digital Entertainment Group (DEG) estimates that overall Blu-ray format penetration is expected to hit 45% in the U.S. by 2015, with some 20% of that capacity Blu-ray 3D capable.

Currently, 24 Blu-ray 3D titles are expected to be released widely in stores by the end of 2010, with 3-4 times that number expected in 2011. Depending on the studio, some Blu-ray 3D titles include both 2D and 3D viewing options on the same disc. Other studios are including separate 2D and 3D Blu-ray Discs in the same Combo package. A few studios are releasing Blu-ray 3D ONLY titles - usually titles that have already been released on Blu-ray separately in regular 2D.

Among the Blu-ray manufacturers that are currently adding 3D capability to their players (or have announced plans to do so) are Sony, Panasonic, Samsung, Pioneer, LG, Sharp, Toshiba, Oppo, Marantz, Vizio and Philips.

Note that standard 2D Blu-ray players can't play a Blu-ray 3D title, unless it also includes a 2D option on the same disc. But Blu-ray 3D-compatible players can play both 2D and 3D titles, along with all the usual DVD and CD options.

3D Via Broadcast, Satellite and Cable

Okay, so you can watch Blu-ray 3D movies at home with the right equipment. But if you've got a 3DTV, what else is on in 3D?

Right now, there are relatively few 3D offerings from broadcasters and cable and satellite providers. Select cable operators may each have a couple of dedicated or part-time 3D channels. DirecTV currently has a trio of full-time 3D channels, while Dish Network offers select event programming in 3D. ESPN 3D is one of the only current fully-programmed channel offerings, though Discovery, Sony and IMAX have plans to jointly launch a 3D channel in 2011 and more are sure to follow. You're also starting to see a lot of marquee sporting events broadcast in 3D, including the recent FIFA World Cup and The Master's Golf Tournament. ESPN 3D is also broadcasting select MLB, NBA and college football games in the format. But right now, the selection is still limited - a situation that will start to change as more 3DTV displays arrive in homes.

ESPN 3D

3D Video Games

Sony has recently offered a firmware upgrade that allows their PlayStation 3 video game system to play Blu-ray 3D movies and fairly simple games. The 3D game titles are available both as downloads and on disc, but most of them (though not all) are upconverted 2D titles. To really take advantage of the 3D experience, a game has to be designed from the start for 3D play. It's more time-consuming and expensive to do that, so it will take time for the leading game studios to make that leap. For the next few years, 3D gaming at home will also be fairly limited.

However, it's likely that at least a couple of next generation of major game console systems (from Sony, Nintendo and Microsoft) WILL be designed from the start with 3D gaming in mind. Once those arrive a few years from now, and truly great and elaborate 3D gaming experiences are available and affordable - that's when we here at The Bits really think 3D at home will start to take off. Gamers have little problem paying extra to upgrade hardware, accessories and software, provided they get a quality gaming experience for their money and effort. Improvements in graphics, sound, motion control, tactile feedback and interactivity are all advancing at a tremendous pace. But the simple fact is, 3D is really the last missing piece of an "ultimate" and truly immersive virtual game experience. We can easily imagine new headgear that incorporates active shutter 3D glasses, surround sound speakers, force feedback and voice communications all in one unit. Imagine playing a future edition of Halo or Call of Duty with an accessory combat helmet that delivers the action in 3D. We have little doubt that the 3D gaming experience is coming, that it will be used by game studios and console makers in new and unexpected ways... and that many gamers will embrace it.

Sony's PlayStation 3 offers 3D gaming

But I Hate Those Damn Glasses!

Don't worry: you're not alone. Lots of other people hate them too, including us. If the need for 3D glasses is what's holding you back from embracing the technology, there's good news and bad news. The good news is that Autostereoscopic (meaning without glasses) 3D displays ARE possible, and have been already demonstrated. (See this article in Wired from 2008.) The bad news is that getting it right requires at least a doubling of existing display resolution and much higher data/refresh rates. Current HDTV has a resolution of 1920 x 1080 - that will need to double to at least 3840 x 2160. This WILL happen... eventually. But given that most of the world has only recently converted to 1920 x 1080 HDTV in ernest, most industry experts believe that those higher resolution displays are at least a good decade away from being affordable, mass market products. Not to mention the fact that there's no use in even making such equipment if there's little content to view on it. So 3D without the glasses is coming and it's almost certainly the future of television... but let's just say that we wouldn't suggest anyone hold their breath waiting for it.

So Should I Buy 3D Now... or Wait?

That's really up to you. So much of the film and consumer electronics industries is backing 3D now that there is little doubt the 3D experience is here to stay. More new movies will be shot natively in 3D, more older catalog films will be up-converted to 3D (a process that takes time to do properly), more titles will be released on Blu-ray 3D format, and more HDTV displays and Blu-ray players will have 3D-compatibility built in. As I said earlier, 3D will probably simply become a standard option in all new equipment within a year or two. But given that it's all still relatively new technology, bringing that experience home is going to cost you more now than it will in the future. And as with all new technology, it will improve over time... meaning that the 3DTVs, active shutter glasses and Blu-ray 3D players you buy now may not deliver as good an experience as future models, once all the bugs are worked out.

It's also important to note that until the audience for Blu-ray 3D grows larger and more active, many of the best catalog 3D movie titles aren't going to be available yet. And some of the most desirable new titles - think Avatar 3D - are already tied up as manufacturer exclusives, available only to consumers who buy certain brands of Blu-ray 3D player or 3DTV display. This is frustrating if you happen to be an early adopter who's purchased a different manufacturer's hardware. So what you'll have available will mostly be kids titles, CG animated fare and big new epic, action and sci-fi films.

Still, if you're REALLY excited about 3D in the home, you have the extra money to spend and you just can't wait, everything you need to start enjoying 3D in your living room is now available. But for the vast majority of you, our suggestion is to wait a year or so. By the holiday shopping seasons in 2011 and 2012, there will be many more choices of equipment, it'll all be better and cheaper, and you'll have a lot more Blu-ray 3D movie titles - not to mention more 3D channel offerings - available to enjoy.

For those of you who DO want to upgrade to 3D in the near feature, remember that you can do so gradually, a piece at a time. Do you really need a new HDTV? Look for one that's 3D ready. Is your first-gen Blu-ray player on the fritz? New Blu-ray 3D-compatible models start under $300. Once you have those two components, all you need to add is a 3D-upgrade kit from your TV's manufacturer (which includes the glasses and transmitter) and you're all set. Buying the technology a piece at a time can ease the financial cost and spread it out over time. Just remember: When you're replacing or upgrading A/V equipment, it's always smart to make future-proof buying decisions if they're affordable.

Meanwhile, 2D movies and TV programming look just fine, thank you very much. And with lots of standard Blu-ray players and movies now available, not to mention plenty of fine 2D HDTV displays, there's never been a better and more affordable way to view them.

So whether it's in 3D or good old 2D, our best advice is just to enjoy some great movies!

Bill Hunt
billhunt@thedigitalbits.com