All sorts of 3D glasses can be divided into 2 classes: active and passive. Active 3D glasses interact wirelessly with pictures on a screen to improve 3D viewing, while passive glasses don’t. Passive 3D glasses have been about since 3D viewing first arrived in the 1920s, and are they split into two major subcategories: anaglyphic and polarized glasses. Practically anyone that has ever seen a 3D movie is acquainted with anaglyph glasses, which feature a mixture of red and blue lenses.
Anaglyphic 3D works by projecting 2 matching but a little offset photograph on a screen, each image tinted with a different colour. To the Naked eye, an anaglyphic image appears foggy, with red and bluish colours.
The glasses use colour-filtering lenses to target one image to the right eye, and another to the left ; the result’s that each eye sees a different image, but the mind is duped into believing it sees just one. The mind compensates for this by targeting between the 2 offset photographs and mixing them into one, which creates an illusion of depth. Passive polarized glasses operate on the same basis as anaglyph glasses, only they filter light waves instead of colour. Again, 2 matching and a touch offset pictures are superimposed, except in this situation each image is polarized to project light differently than the other. With polarized 3D glasses, each eye only processes one image.
Again nevertheless, the mind is conned into mixing the 2 pictures into one, making a 3D experience. Unlike anaglyphic 3D, which can be projected from any screen, polarization 3D works best with screens in a position to relay different light frequencies without sacrificing picture definition. On a faster scale, Pulfrich glasses can also make a 3-dimensional appearance, but only with objects moving across the viewer’s plane of vision. These 3D glasses have one absolutely clear lens, and another that’s heavily coloured. As an object moves across the idealist plane, the image is instantly broadcast to the eye thru the clear lens, but the colored lens causes a slight delay. This delay causes the brain to add more depth to the image, making kind of a 3D appearance.
Since the arrival of LCD technology, which is really capable of digitally broadcasting pictures at super high-speeds, 3D glasses have made great technical big leaps. Today, active shutter glasses can communicate wirelessly with an LCD display, interacting with the action on the screen thru infrared signals. This can enable the lens on active glasses to shutter backwards and forwards between different light filters, further augmenting the 3D viewing experience. Another serious upside to active technology is that it’s flexible to 3D TV sets. A 3D-ready TV set, two active shutter glasses, and a stereoscopic sync signal connector will permit the LCD display and glasses to speak with each other. An increasing number of TV broadcasts are being produced to milk this technology.