- Becoming a craze in the late 2000s and remains still, paired with IMAX to create spectacular film experiences
- Polarization – projectors project image onto the same screen, one for each eye
- Runs at 144 frames per second
- Glasses at different polarizations, cancel out the other to create comprehensive 3D image
- Curved to prevent cross talk
Conclusion: While 3D is thought by many to be no more than a gimmick, there is a surprising amount of effort and technology that goes into creating these realistic effects in a movie theater.
What’s the last 3D movie you’ve seen? In the theater, as you saw places and people pop out at you, did you ever stop to wonder exactly how those movie projectors and big plastic glasses work to create the stunning 3D images you see? 3D has been around in one form or another since the 1950s, and the technology that makes the 3D effect happen is fairly straightforward, but amazing nonetheless. 3D movie technology has evolved a great deal since the monster movies of the 1950s, moving from the red and blue glasses of the old days to newer polarized effects that lend a more ‘real’ feeling to 3D movies.
In order to understand how 3D works, we have to understand how we normally use our eyes to perceive the world. We normally see in 3D through a concept psychologist and visual perception researcher Ian Howard calls ‘binocular vision’. In essence, our eyes are ever so slightly angled toward each other, giving our brain two sets of images to compare to each other. That comparison gives us what we know as ‘depth perception,’ the perception that things are further or closer to us than others.
This concept is also applied to 3D glasses, which have manipulated binocular vision in a number of ways. The first kind of 3D glasses used ‘red/cyan’ technology, and were the cardboard glasses you sometimes still see today. Author Ray Zone notes that stereoscopic cinema started out all the way back in the 1920s with the film The Power of Love, using red/cyan glasses. Here’s how they work: a film is projected from two different projectors onto the same screen, one in red and one in cyan. When you put on the glasses, each lens filters out its like color, so you can only see the cyan-film through the red lens and vice versa. Since each one shows a different level of depth, the illusion of 3D is created by fooling your binocular vision into thinking each image is at a different depth than it is.
While that was popular for a time, 3D fell out of fashion until the late 2000s, when polarization was popularized by films like Avatar (the highest-grossing film of all time to date, according to the movie revenue-aggregate site Box Office Mojo). With polarization, there is no need to limit to two colors – with this process, two projectors project an image onto the same screen (one with a certain depth for the left eye, the other for the right). Each lens has a different polarization matching its intended projector, only filtering in the projection that was to be seen. This projection happens at a rate of 144 frames per second, too quickly to register any flicker with the naked eye, according to an article in Scientific American. Unlike the flat cardboard glasses of the old days, tech writer Erez Ben-Ari notes that the curved, plastic polarized lenses prevent ‘cross talk,’ which is when one eye notices the other projected image in their periphery because they can see the image from the other lens. With this, 3D images are now more real, and can be shown in full color for a completely immersive experience.
While 3D is thought by many to be no more than a gimmick, there is a surprising amount of effort and technology that goes into creating these realistic effects in a movie theater. From the old days of cardboard lenses and 1950s monster flicks, to the ultra-realistic 3D that allows detailed, full-color images to pop out at you, 3D technology has advanced a long way from how it started. The next time you go to the theater and see those incredible space battles or giant monsters running toward you, I hope you remember what you’ve learned from this presentation and know just a little bit more about the magic behind the movies.
Works Cited
Ben-Ari, Erez. "How 3D works, and why it's back." TechFlash: Seattle's Technology News Source. 4 Feb. 2010. Web. http://www.techflash.com/seattle/2010/02/the_science_of_technology_how_3d_works_and_where_its_headed.html.
Box Office Mojo. “Avatar.” Box Office Mojo. 2014.
http://boxofficemojo.com/movies/?id=avatar.htm.
Howard, Ian . Perceiving in Depth. New York: Oxford University Press, 2012.
Kuchment, Anna. "PATENT WATCH." Scientific American 303.5 (2010): 30.
Ray Zone, Stereoscopic cinema & the origins of 3D film. University Press of Kentucky, 2007.
