There are two competing technologies that create 3D effects: passive and active. Active has been the most widely used 3D TV technology. However, new passive technology is rapidly gaining in popularity due to its lightweight and inexpensive glasses, allowing for more people to enjoy 3D TV together. Learn what active 3D and passive 3D mean when choosing a 3D TV.
In addition to how active 3D and passive 3D technologies actually work, the main difference is the 3D glasses that are used with them.
ACTIVE 3D
Active 3D works this way: An electronic signal is paired to active shutter 3D glasses from the TV and it opens and closes—or "shutters"—the left and right lenses of the glasses rapidly to match the images on the screen. In other words, they dim the left lens and then the right lens in quick succession. The brain sees the fast-moving alternating frames as 3D.
The complicated technology can make the active eyeglasses expensive and heavy.
PASSIVE 3D
Passive 3D operates by separating images for each eye and then converging them to deliver the 3D images. Different kinds of light are blocked in each eye and this creates the illusion of depth. This allows the 3D passive glasses to be significantly more affordable and lighter than active glasses.
Some say the passive 3D TV picture resolution quality is not as good as an active 3D TV, although recent 3D TV tests have shown consumer preferences for the passive 3D TV picture image.
What is 3D?
3D imaging is almost as old as photography. It is also known as stereoscopy and takes its name from the Stereoscope, probably the earliest form of entertainment that created 3D images. 3D is basically any technique that can record three-dimensional visual information or that can create the illusion of depth in an image.
How is the 3D Effect Created?
To create a 3D image, two slightly different images are beamed onto each eye. The brain sees two images, each coming from a different location (an eye), and generates an illusion of depth. Special glasses are needed to create the 3D effect in both theaters and at home.
3D Glasses & Viewing Angles
Viewing angle refers to the position at which you watch a TV. Active 3D glasses may have poor signal quality at extreme angles. This can limit how many people can watch at one time. Passive 3D glasses do not have such strict limitations. Learn more about 3D Glasses
