What are 3D Glasses?
3D glasses are optics worn primarily during movies, which immerses the viewer into the media by bring the images out of the viewing screen and into the world, by manipulating how the viewer's eyes see the image.
What Types of 3D Glasses Are There?
There are three types of 3D glasses, anaglyph, polarized, and shutter.
Anaglyph glasses, are a type of passive 3D glasses (meaning they require no input from the display the viewer is using) which utilise two different coloured lenses, primarily red and blue the filter out red and blue colours in an image or video which has two exposers of the image, one in red and blue respectively. The glasses filtering of the colours creates the illusion of 3D, by making each eye see the image in slightly different locations, which the brain then merges into one location causing the image to look like it is coming off the page or viewing platform. This variant was created in the 1850s, by Wilhelm Rollmann.
The main advantage of this type of 3D glasses is that it is easy to create as it only requires one red and one blue lens.
The main disadvantage of this type of 3D glasses is that due to how the 3D image is created, it forces any media it is used with to be in primarily red and blue colouring.
Polarized glasses (also passive) work in a similar to anaglyph as they are also blocking part of the whole image to create a 3D experience. The main difference with these glasses is that instead of blocking individual colours, these glasses block rows of pixels which differ for the left and right side, creating the 3D image, and do not have coloured lenses although the lenses tend to be a brownish yellow colour. Edwin Land introduced this type of 3D in 1936
The major pro to this type of 3D glasses, is that they allow for watching movies or viewing images in full colour, and this type of 3D glasses are relatively cheap to manufacture.
The major con with this type of 3D glasses is that on most modern household 3D displays these glasses don't allow for full 1080p images as they require blocking pixels in order to work. In addition these type of 3D glasses can add a yellowish brown tint to images.
An example of pixels being blocked by polarized 3D glasses.
Shutter (RF) Glasses
This type of 3D glasses are active 3D glasses meaning they communicate with the display to determine how to create the 3D image. These glasses have LCD screens for lenses which block the display's light from entering one of the users eyes in order to create the 3D image. These 3D glasses use radio frequency in order to communicate with the display to determine when to block an eyes view and how fast to block it. These glasses typically alternate showing and hiding the display from the users eye at about 60 frames a second (the standard TV refresh rate).
The biggest advantages to this type of 3D glasses is the fact that these glasses allow for full 1080p resolution, and don't alter the colouring of the images the viewer is seeing.
The biggest cons with this type of 3D glasses are, these glasses require batteries to operate, can darken the light coming from the viewing screen, and can cost up into the $200 range.