The decision by Walt Disney Co. and Dolby Laboratories Inc. to equip 100 U.S. movie theaters with digital projection systems for the 4 November premier of the three-dimensional film Chicken Little marks a turning point for digital cinema, a technology poised to completely change the way theaters show movies [see picture, "Digital Conquest"]. It may also turn 3-D movie projection from a seldom-used gimmick into the commonplace.

The technology for digital cinema—encoding and decoding software, file servers, and special projectors—has been available for years. But until now, only some 250 screens worldwide have used it. Two big hurdles have prevented widespread adoption. First was the lack of a standard—theater owners making the investment in a digital cinema system, at a cost of about US $100 000 per screen, had no guarantee that the product they purchased would be compatible with the next theatrical release.

"I don't think we would be able to successfully migrate to digital cinema without a standard," says Steve Jacobs, vice president of engineering for Dolby in San Francisco. "You would wind up with too many competing formats."

Second was the problem of who pays that $100 000 to convert each screen. Not too many theater owners were willing to open their wallets, and no one else was stepping forward.

This year things changed. A group of seven movie studios, incorporated as Digital Cinema Initiatives LLC, finalized a standard on 27 July, with lots of input from the equipment makers and theater owners. And Disney and Dolby decided to pay the bill for complete digital cinema systems at 100 U.S. theaters, increasing by nearly 50 percent the number of digital screens worldwide. This is the first time a movie studio has paid the bill for anything more than test systems in theaters, and it could be a sign of how the changeover may be supported.

The intrinsic desirability of using digital technology in 3-D projection gave Disney and Dolby a powerful motive to advance the technology. Digital projection makes 3-D movies cheaper, because instead of two film projectors, just one is required. A processor card interleaves two image files for 3-D viewing or simply drops one for 2-D viewing. Three-dimensional films done digitally also have the benefit of not being limited to 24 frames per second.

At 24 frames per second, alternating images for the right and left eye, while barely perceptible, reduces the overall clarity of the movie; speeding up the frame rate eliminates that problem. November's release of Chicken Little will exploit this capability: theatergoers wearing 3-D glasses will see the sky falling in 3-D at 144 frames per second.

Of course, distributing films digitally reduces costs enormously. Instead of multiple reels of film being produced and shipped, distributors send the movie to the theater as a digital file on a hard drive. The digital data are then copied into a server, which feeds a digital projector and sound system. The projector fills the screen with a series of red, green, and blue rectangular pixels, in the same way computers and digital televisions display images.

Given the anticipated savings, expecting movie studios to foot at least part of the bill for the transition seems reasonable. A film print of a movie costs about $1000 to produce, and if a movie is an unexpected hit, it may take days to increase the number of prints in circulation. Digital copies can be added to new screens within a multiplex within an hour, on the other hand, and in the future, satellite transmission systems will make such distribution nearly instantaneous. Digital copies of a movie do not need to be replaced, unlike film, which wears out after multiple showings.

Once the world's movie theaters go digital, movie studios expect to save about a billion dollars a year.