davy (03/10/83)
#N:pur-ee:7000029:000:822 pur-ee!davy Mar 9 22:29:00 1983 Last night I saw a double feature of two 3-D movies. We won't discuss the technical merits of them, because there weren't any. I purposely went on dollar night, because I had never seen a 3-D movie before, and was curious. Now I'm thinking though: How do these 3-D movies work? They give you a set of glasses, with one red and one blue lens. So, I gather that one eye gets one image, and the other eye gets another image. The thing I don't get is: 1. How does seeing two different copies of the same image make it 3-D? Are the images "next to each other", or "one closer than the other", or what? 2. How come when I took the glasses off, the movie was in color, but when I put them on, it was in sort of black and white (except for yellows, etc.)? --Dave Curry pur-ee!davy
pvl (03/10/83)
I understand how the Red/Blue coding works, but while we're at it, can anybody explain how the Polarized movies manage to get polarized movies into standard theatres. Are special projectors/filters used?? Pete LaMaster BTL NJ (201)949-0040
jjm (03/10/83)
3D movies attempt to recreate the method by which you normally see things. That is, each eye gets a slightly different image, because it is looking at the object from a different position. This difference in viewing angle is referred to as inter-ocular parallax. 3D movies attempt to provide each eye with a different image, filmed from a pair of cameras (or other arrangement). The brain combines these two images, and voila! 3D. Two ways of doing this are A) color code two images and view through tinted lenses and B) polarize the two images and view through polarizing filters. Method A can be projected using a standard projector. Method B requires a special projector (or pair of projectors) projecting through polarizers. Most available 3D films are trashy because of three problems: A) poor filming equipment lets the images get out of alignment B) poor projection equipment makes it worse C) most directors (and cameramen) have not taken the time to perfect the art of direction and filming in 3D. American Cinematographer magazine had a special issue recently about state-of-the-art 3D filming. Special 70mm film is used, allowing the split images (each 35mm) to be recorded on the same frame. Special digitally controlled projectors are used to reduce "jitter" (a framing problem) when projected. A special screen is used that does not de-polarize the light it reflects. Disney World's new attraction "EPCOT Center" includes a special 3D theatre, showing a specially produced film. Rumor has it that the effect is marvelous, using multi-speaker digital audio to enhance the effect. Jim McParland American Bell - Holmdel hou5e!jjm
bsw (03/11/83)
I kind o know basicly how 3D works with red/blue glasses,but I won't (can't) explain it (because I really don't know that much on it)(confusing,ain't it?). But, I have a pair o 3D glasses that work, but the lenses are both of black(kindof coalish color) Can anyone tell me how these work ? Ben Walls -cbosgd!bsw