In order to understand the difference between the 3D technologies and glasses, we first need to understand how 3D works. 3D content has 2 sets of videos (or frames), one for each eye. In order to see the 3D effect, we need to make sure that each eye sees only the video or image that is intended for it, which is why we use 3D glasses. All 3D glasses are equipped with special lenses that make sure this will happen, they filter only the left frame to the left eye and the right frame to the right eye. The difference between each type of 3D glasses is in the way they do that.
Let’s go over the main types of 3D glasses and technologies being used today.
Polarized 3D glasses are the most common 3D glasses used in cinemas today. The glasses have special lenses that filter the intended frame to the correct eye using differences in light polarization, or “direction”. To use these glasses, a compatible 3D display or projector is required, which polarizes light differently for each eye. The advantages of Polarized 3d glasses are that they provide a very good 3d effect and the glasses are cheaper and more comfortable than the active glasses. One of the disadvantages of Polarized 3D glasses is the need to use a special silver screen with a projector, which makes the system more expensive, and slightly decreases the 3d effect in comparison to the active systems. There are two main types of polarization: linear and circular. The circular type of polarization allows a viewer to tilt their the head more than with the linear system, without losing the 3D effect. This is why it is used more often in cinemas and with some 3D TV’s.
Similar names: Wave length 3D glasses, Passive 3D Glasses, Real D 3D Glasses, IMAX 3D glasses, Master Image 3D Glasses, DepthQ 3D Glasses.
Anaglyph 3D glasses are the simplest type of glasses of the ones we will discuss here. They have lenses in two different colors, usually Red and Cyan, but other color combinations can be used such as Green and Magenta. The colored lenses of the 3D glasses filter each frame to its designated eye corresponding to color differences in the 3D movie. The main advantage of Anaglyph 3D glasses is the low price and that there is no need for a special display for watching anaglyph 3D. You can use any standard display or even print an anaglyph picture on a paper. The disadvantage of Anaglyph 3D glasses is the low 3D quality they offer. This is why they are not currently being used in any of the modern cinemas or with 3D TVs today.
Similar names: Red/Cyan 3D Glasses, Red/Blue 3D Glasses, Green/Magenta 3D Glasses, Complementary color glasses.
Active shutter 3D glasses are commonly used with 3D TV’s, 3D projectors, and in some cinemas. Each lens contains transparent liquid crystal that turns black once a voltage is applied, blocking one of the eyes sight at a time. The glasses get instructions from the emitter or screen to darken each lens at the right time, while the screen presents a different movie image to the unblocked eye for the completion of the illusion. For example: when the left lens turns black only the right eye sees the image that the screen intends for it, and vice-versa. There are a few ways communication occurs with Active shutter 3D glasses: through an infrared emitter, a radio frequency emitter, or a DLP-link that uses a flashing technique instead of an emitter. 3D TV’s and 3D PC’s will usually use an emitter, whereas DLP projectors will usually use the DLP-link technology. The 3d effect is very good when using Active shutter 3D glasses. The main disadvantages are that they are expensive, that they are not very comfortable, and there is flickering which can sometimes cause mild dizziness.
Similar names: Liquid crystal glasses, LCS Glasses, LC shutter glasses, active shutter glasses, Active 3D glasses.
Infitec 3d glasses are actually an upgrade of the anaglyph 3d glasses and are sometimes called “Super-Anaglyph” glasses. Each image for each eye is encoded with slightly different red, green and blue colors. The differences are so slight that our brain hardly notices them, but they are strong enough to be filtered by the glasses’ lenses, and each slightly different image is filtered to the intended eye. The 3d effect of Infitec 3d glasses is very good, but the system is somewhat complicated to set up at home. The infitec 3D system and glasses are being used mostly in cinemas.
Similar names: Super anaglyph, Interference filters glasses, Spectrum separated 3D glasses, Dolby 3D glasses.