Why do we use only red, blue and green colours in 3D glasses?

SUJI

Ramanathapuram, Tamil Nadu

Presence of any object or image on a screen is perceived by the brain from the light reflected by it and received by the eye as stimuli in the human visual (neural) system. The human visual system basically splits the reflected light in to three components corresponding to blue, green and red regions of the visible spectrum.

Also it is possible to produce any colour just by mixing/ controlling the relative intensities of these three colors. Hence these three colours are called primary colours and are quantified in terms of tri-stimulus values.

In order to generate an illusion or impression of real space (both area and depth) of an object or image in a two dimensional projection, three dimensional (3D) glasses are used which is accomplished with the principle of binocular vision.

That is the two eyes of the human visual system placed apart ( about 5 cms ) perceive the object/image from different positions and angles in turn causing response or stimuli as two different images of the same object in the neural- visual system of the brain.

Binocular vision in our brain uses the difference to calculate distance/depth and has the ability to correlate the images it sees in its two eyes even though they are slightly different. In the binocular system, the same scene is projected simultaneously from two different angles in two different colors usually red and cyan (or blue or green). In order to see things in 3D each eye must see a slightly different picture.

The brain then puts the two pictures together to form one 3D image that has depth eventually generating a three dimensional impression. 3D glasses make use any two of these primary colors ( blue, green and red) one for each eye as the intensity of the third colour can be inferred from difference between total light and the sum of intensities of these two colours to get the complete information on colour of the object or image to be seen through the 3D glass.

R. JAGANNATHAN

Luminescence Group

CECRI

Karaikudi, Tamil Nadu

Keywords: 3D glasses

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