| Recently, I met a family which was attending their
18th. IMAX movie.
They traveled in hopes of seeing them all. "IMAX is so wonderful, it seems like magic". |
| This page explains
how "3D" (actually stereoscopic) movies
work.
Hopefully, this explanation won't take away from the "magic" and wonder of IMAX 3D. Its an experience not to be missed. |
| Why is
IMAX different? |
 |
First of all, IMAX is quality. 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. |
| How do things
appear to jump out of the screen? |
Stereoscopic photos and movies, popularly 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. | |
| I watch two
movies? |
Well yes, and special polarized glasses separate the two images. Lets explain how these two separate images are projected first. | |
| In this example,
the top projector is for the left eye. |
The image for the left eye, which was made by the left camera, is projected onto the screen through polarizer #1 indicated by red arrows 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. . |
|
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. Indicated by the red arrows.
The red arrows, (light waves),
from the two images shine down onto the silver screen #3 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.
#4. A magnified view of the screen shows facets, like the bottom of a diamond which bounce the light (red arrows) back out. The screen also has holes in it to let the sound pass through. |
| How are the two
pictures seperated? |
Remember
how the 2 projectors were polarized to project light waves going only in
one direction? Likewise, each lens of the cross polarizing glasses
#5 accept light only in one diagonal 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. As indicated by the red arrows. Magically, the left lens blocks the image for the right eye. And, The right lens blocks all of the image for the left eye. This blocking is represented by the gray arrows. That is how the two distinct images are separated for each eye creating depth. Anything can come right out of the screen and appear to be in your lap or over your head. See "How
Polarizers Work" to intensify color in photography. Then
some Stereo photos.
|
| Where
can
I see an IMAX 3D movie? |
Take me to the Tennessee Aquarium
and the 3D IMAX
theater in Chattanooga.
Take me to the IMAX
headquarters in Canada for the most information..
Take me to the IMAX theater in Atlanta at the Fernbank Museum of Natural History. The phone number for show times is 404-370-0019. Note: Recordings and web site may not be accurate, but you can continue down Clifton Rd. to Everybody's pizza and wait for your show. |
| As a reward
for reading so much, enjoy the stereo picture below.
Stare at the fish and let
your eyes drift off into the distance.
|
..
.