Image by Megaplex Theatres
Ever been wondering how does the 3D movies that you’ve seen in the cinema seems 3 dimensional-like? And why does it looks like it has somehow pops out from the screen?
Turning a flat image into one that pops out of the surface is all about depth perception. In order to appreciate depth, your brain needs to see two different angles of the same image just as we get with our binocular, two-eyed, vision. So, the main principle of 3D imaging is to send one angle of a picture to your left eye and a different angle of the same scene to the right, which your visual cortex will then put together as an object with depth. Well, that’s the theory.
The earliest confirmed 3-D film shown to a paying audience was The Power of Love, which premiered at the Ambassador Hotel Theater in Los Angeles on September 27, 1922.The camera rig was a product of the film’s producer, Harry K. Fairall, and cinematographer Robert F. Elder.It was projected dual-strip in the red/green anaglyph format, making it both the earliest known film that utilized dual strip projection and the earliest known film in which anaglyph glasses were used.Whether Fairall used colored filters on the projection ports or whether he used tinted prints is unknown. After a preview for exhibitors and press in New York City, the film dropped out of sight, apparently not booked by exhibitors, and is now considered lost.
Early in December 1922, William Van Doren Kelley, inventor of the Prizma color system, cashed in on the growing interest in 3-D films started by Fairall’s demonstration and shot footage with a camera system of his own design. Kelley then struck a deal with Samuel “Roxy” Rothafel to premiere the first in his series of “Plasticon” shorts entitled Movies of the Future at the Rivoli Theater in New York City.
Kelley, who was an early producer of color films, used Prizma to print his anaglyph films. In early 1923, he shopped around a second Plasticon entitled Through the Trees – Washington D.C., shot by William T. Crespinel, which consisted of stereoscopic views of Washington, D.C., but found no buyers.
Now, there are 4 different methods of observing a 3D movie – Anaglyphs, Infitec (Interference Filter Technology), Polarized Light, and LCD Shutters (Alternate Frame).
Anaglyphs
Image by Osvescen
When we spoke to people about 3D glasses, it’s most probably that they’ll think of red/cyan one from the anaglyph system. The real trick of 3D isn’t superimposing two slightly different images onto a screen but getting your eyes to separate them again, and that’s what the colour filters are all about.
The whole image of an anaglyph is base on two colors: one picture layer for one eye in reds and the other for the other eye in cyan shades. These two colours are used because they’re opposites to one another. So, when the viewer looks at the resulting image through the red and cyan filters in the glasses, each eye sees one whole layer from a different angle to the other eye without seeing any of the other layer at all. The separate pictures from the two eyes are sent to the brain where the 3D stereo image is formed.
Infitec (Interference Filter Technology)
Image by AVS Forum
Infitec is the future of anaglyph and it is somehow referred as super-anaglyph. Instead of splitting the image into the utmost fundamental colors, the points of view for each eye use narrow but different bandwidths of blues, reds and greens. This, in turn, the left and right eyes are actually seeing slightly different and distinct wavelengths of reds, blues and greens to each other, but it’s not noticeable to human perception.
Polarized Light
Image by PolarizedOptics
Nowadays, the most auspicious ways to make a 3D work in a movie is to polarizing two separate light. In the cinema, two projectors could be used to shine synchronised images at the same screen providing the right and left eye perspectives. The two projectors would have opposite polarising filters over the lenses to make sure they only let through light travelling in one orientation each. The audience then wears glasses with the same two polarised filters over their eyes, such that each eye can decipher one of the images from one of the projectors. Then, once again, the two distinct and different pictures are sent from the eyes into the visual cortex where the brain puts them together in 3D.
LCD Shutters (Alternate Frame)
Image by FareastGizmos
This glasses contains liquid crystals and a polarising filter have a property which means, when you pass a voltage through them, the lenses turn black, thus obscuring one eye’s view through them. This can be done alternately in time with the frame rate on a TV or projector image as controlled by an IR signal from the screen. The idea is that the one display can be firing two separate images alternately for each eye as the other eye is covered up.
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My pleasure 😀
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