Digital 3D uses polarization to make a 2D image appear three-dimensional. Typically used in movies, polarized glasses are required to see the 3D movement, but images can also be viewed without lenses, though they may appear blurry. Digital 3D does not use color variation, which used red, blue, and green to create 3D effects in older movies.
Human eyes are binocular. This means each eye sees a different portion of an image, and the two are combined to create one image in the brain. Traditional 3D images are color coded red and blue. Lenses worn with corresponding colors allow eyes to see images that appear to have depth beyond the screen. Using color variants can cause images to appear off color.
Digital 3D uses many of these concepts, but replaced color variants with polarization. Images are polarized and glasses worn with lenses made of different polarizations create a 3D effect. Movie theaters typically use one or two projectors to display digital 3D movies on screen. If one projector is used, a switch may be installed to control image polarization. When two projectors are used, images are displayed to both eyes simultaneously.
Digital 3D animation started slowly in movies. Chicken Little was first released in North America in 2005. Digital animation was used to create the film, which was later rendered for 3D viewing. Later, previously released movies, like The Nightmare Before Christmas, Toy Story, and Toy Story 2, were re-released as 3D movies.
Today, watching 3D movies on home television sets requires the use of 3D glasses. The electronics company Philips was the first to develop a home television that can display digital 3D images without glasses. With it, a lens is placed on the surface of the television to create a digital 3D effect. Traditional television stations or movies tend to appear blurry on this set, however, and consumers report that images can be distorted from certain angles.
Digital 3D images are also found on the Internet. These images do not use the same 3D technology as movies and television. Usually, these use shadows and movement to trick viewers into seeing what appears to be a 3D image on screen. Digital art and computer wallpapers are also commonly found in digital 3D.
One of the more popular 3D art pieces is the autostereogram. The images represent a 3D picture placed within a 2D work of art. When eyes are forced out of focus, a second image can typically be seen. Some viewers report feeling a pulling of eye muscles as they concentrate on one of these hidden pictures.