There’s a new kid on the technology block and its name is passive 3D. It brings a whole new depth to your favourite movies, TV shows, sports, and 3D video games using some of the lightest 3D glasses around.
Passive 3D technology is all about letting you relax and put your feet up as 3D movies, TV shows, high-action sports, and video games come alive right before your eyes. Passive 3D TVs and 3D glasses recreate the 3D effect using an almost effortless process. These special glasses are also so lightweight that you might even forget you’ve been wearing them through all 2.5 hours of Avatar.
So, how exactly does passive 3D work? And what makes it different from that other three-dimensional technology, Active 3D? There’s a lot to learn about passive technology, but first let’s get some background on what 3D is all about.
What is 3D?
3D, or stereoscopy, refers to the illusion of depth in an image. It means that your brain can be tricked into thinking that flat, two-dimensional images are actually solid. The result is that your eyes see a physical, three-dimensional image even though it’s really just a flat picture on the screen. And the cool thing is that it’s not magic. 3D TVs recreate stereoscopy by projecting two different images on screen and using 3D glasses to turn them into one three-dimensional picture.
There are two kinds of technologies used by 3D TVs – active 3D and passive 3D. Each produces stereoscopy in different ways, giving you two unique 3D experiences:
Active 3D televisions work by alternately displaying one image for your left eye and then, one for your right eye, in quick succession. These TVs send a synchronization signal via infrared technology to liquid crystal shutter glasses. The lenses on these glasses are actually small LCD screens that alternately shutter open and closed in sync with the images displayed on the TV. For example, when the right eye image is on screen, the left lens closes, so only your right eye will see the image. This shuttering happens so quickly that you don’t even notice one lens is closed at any point. The result is a 3D picture so clear, you could almost wrap your arms around it.
Unlike active 3D, passive 3D televisions show one image to your left and right eyes simultaneously. These TVs have circularly polarized light filters in their screens that separate the picture into left and right images for each eye. The lenses in passive 3D glasses are also polarized, so that only the left image enters the left eye and only the right image goes in the right eye. The images then combine in your brain, tricking you into seeing three-dimensional depth.
The name passive 3D refers to the fact that polarized 3D glasses don’t require any built-in electronics in order to see the 3D effect. The TV filter does all the work to create stereoscopic 3D, so you just see the image when it passes through your glasses.
Passive 3D vs. Active 3D
Passive and active technologies can both produce 3D, but that’s where most of the similarities end. There are a number of factors that make passive 3D different from active 3D:
Active 3D Passive 3D Winner
3D Glasses The built-in electronics and batteries can make them heavy and uncomfortable. These glasses are generally expensive and you’ll need to buy replacement batteries every so often, which can add up over time. No circuitry or batteries needed. Just like wearing regular glasses, passive 3D glasses are lightweight, inexpensive, and comfortable to wear for long periods of time. Passive 3D
Resolution Each eye sees the whole image and its full resolution every time the shutters are open. This helps you perceive a higher picture quality. Even though you’re seeing the same image in both eyes, the polarized filter has to split the image in order for you to properly see the 3D effect. This means that each eye will only see half of the full resolution, resulting in slightly lower picture quality. Active 3D
Brightness Less light passes through the lenses of active 3D glasses, resulting in slightly darker images. Passive 3D glasses allow more light in, so images appear brighter. Passive 3D
Crosstalk Crosstalk happens when you see both right and left images on the screen, instead of one unified image. Active 3D sets can have problems separating left and right images, so crosstalk often becomes a problem. Passive 3D sets generally have little or no crosstalk issues. Passive 3D
Flicker Flicker occurs when you subliminally notice the picture refreshing from a left image to a right image, which creates a “flickering” effect. Slow shuttering of the active 3D glasses is a common problem that can cause this effect. Passive 3D sets don’t flicker at all. Passive 3D
Picture Quality Images are smooth and crisp, which can create an even richer 3D experience. Image edges can appear jagged, but picture quality is still quite sharp. In fact, sharpness can increase the further you sit from the TV. Picture quality varies very little between the two
Things to Know
Passive 3D TVs will work with most polarized 3D glasses regardless of brand, which can save you the cost of buying new glasses if you ever upgrade your 3D HDTV. Keep in mind that the 3D picture and performance may differ between brands and devices due to slight differences in things like lens tint and screen filter.
Clip-On 3D Glasses
Wearing 3D glasses over your normal glasses isn’t just a pain, it’s a fashion don’t. Luckily, there are passive 3D lenses that clip easily on to your frames, so you can comfortably watch 3D and look cool doing it too.
No Flickering with Other Devices
Passive 3D glasses won’t introduce screen flicker (black lines on the screen) if you wear them while using devices like your laptop, smartphone or tablet. This means that you can watch the big game in 3D on your television and easily switch to your computer to surf the web for interesting commentary without giving yourself a headache. The screen may appear darker though because of the filter in the lenses.
Easily Watch 2D Content
Both passive and active 3D TV’s can easily display 2D content without sacrificing picture quality in any way. In fact, these televisions usually come with the best specs overall. So go ahead, take a break from the third dimension and watch your current favourite TV shows in all their 2D glory.
Other Passive 3D Devices
Televisions aren’t the only ones getting a 3D upgrade. There are a number of devices that are starting to use passive 3D technology as well:
3D projectors give you the ultimate theatre-like experience at home. Polarizing projectors usually use a special silver screen that properly reflects polarized light. Other passive setups use two different projectors to create the 3D effect, but these can be expensive and bulky, and are better suited for commercial applications. Luckily, there are some newer models that work great for home theatre use and usually have two small projectors built inside one projector hub.
If you prefer watching movies using your computer or love playing 3D computer games, then you’ll want to get your hands on a 3D monitor. These monitors bring all the action to life in an up close and personal way.
3D is now a popular home theatre option and if you want to make the most of your passive 3D set, these devices could help:
3D Blu-ray players
A 3D Blu-ray player lets you watch blockbuster films, your favourite TV shows, and larger-than-life documentaries in stunning, high-definition Full HD 3D.
Receivers are audio and visual wonders. One of the main things receivers do is amplify the sound in your media to amazing depths and dimensions. Many new models can also convert DVD standard-definition images into Full HD. To make the most of your passive 3D set up, simply connect your devices, such as a 3D Blu-ray player, to a 3D receiver and you’ll get ultra crisp, crystal clear audio and images that will make watching your favourite 3D flick even better.
3D Video Game Consoles
3D puts a new spin on your average video game. Many video game consoles, such as the PlayStation 3, are getting software and hardware upgrades to support 3D gameplay.
Take the Next Step
Ready to take your new passive 3D technology knowledge to the next level? Then check out Best Buy for the hottest selection of passive 3D TVs, 3D glasses and accessories.