How Imax 3D Movies Work

Above:
Amazing T-Rex Imax Movie!

Stereoscopic photos and movies, popularily known as 3D, are made with two cameras, each recording an image for each eye. Consequently, true color stereo requires two projectors to shine on the screen. With a separate image for each eye, one can see depth. Images 'float' right out of the screen in front of your face.

You are actually watching two movies, and special polarized glasses seperate the two images. Let's explain how these two seperate images are projected first:

The image for the left eye, which was made by the left camera, is projected onto the screen through polarizer #1. Think of a polarizer as a screen or filter which is so tiny that it only lets light waves pass through which go from the lower left to the upper right. .

How 3D IMAX Movies Work:

Likewise, the image for the right eye, which was made by the right camera, is also projected onto the screen through polarizer #2. This polarizer allows only light waves going from the upper left to the lower right to pass through.

The light waves from the two images shine down onto the silver screen, making 2 pictures on the screen. The reflective surface of the silver screen bounces the light back out at nearly the same direction, and polarization, that it came from. The two images remain polarized.

A magnified view of the screen would show facets, like the bottom of a diamond which bounce the light back out. The screen also has holes in it to let the sound pass through!

Remember how the 2 projectors were polarized to project light waves going only in one direction? Likewise, each lens of the "cross polarizing glasses" accept light only in one diagonall direction. The left lens accepts light waves oriented from the upper right to the lower left.

Likewise, the right lens accepts light waves oriented from the upper left to the lower right.

Magically, the left lens blocks the image for the right eye. And, The right lens blocks all of the image for the left eye.

That is how the two distinct images are seperated for each eye creating depth. Anything can come right out of the screen and appear to be in your lap or over your head!

IMAX ® and IMAX ® stereo, are registered TradeMarks (TM) of Imax Corp. Mississauga, Ontario, Canada.

Above:
The Rugged Imax Camera

Above:
The Massive Imax Projector

IMAX is film technology pioneered in the 70's by a Canadian company. Each frame of the movie is nearly the size of the film used in a 4" by 5" camera. The reel of film for the projector is so big it lays on a table. The screen is the size of a basket ball court. The sound system is always multi channel stereo from several CDs. It is reproduced through numerous speakers around the theater and from behind the screen. Sounds can appear to come from almost any source.