VIRTUAL REALITY

HOW MUCH IS THAT IMAGE IN THE WINDOW?

Jaded New Yorkers are accustomed to bizarre spectacles. But even the most hardened recently took pause at the sight of full-motion holographic images prancing in space in front of a store window in Union Square.

The apparitions came courtesy of a new technology from a local company called Dimensional Media Associates. Using a complex array`of optics and multiple projections, the company has come up with a technique it calls "augmented reality," which projects three-dimensional videos that seem to float in air.

The New York demonstration consisted of point-of-purchase advertising for the opening of a department store. Video footage of products ranging from blue jeans to ironing boards appeared to be suspended outside the window, where passersby labored in vain to touch the remarkably realistic, full-color images.

The system works by collecting light from video sources such as laser discs. The signals are fed to a computer, where they are synchronized and passed through a patented optical system. From there, the images are focused and projected into space. Depending on the hardware, the technology is capable of projections ranging in size from a few inches to 20 feet. The viewing angle can be as wide as 120 degrees.

While advertising seems a natural for this new medium, the company is working on wider applications. Perhaps the most intriguing is the concept of "virtual surgery," which will allow for a full 360 degrees of image simulation, with none of the cumbersome body wear now requires for virtual reality applications.--Ron Goldberg

Popular Science Feb. '95


HANDS ON

TRICK OF THE LIGHT

ASM Las of Marionville, Mo. claims that its Mongoose fiber-optic cable system, in which analog audio signals travel as light, is immune from interference. But is it worth the cost--starting at $649 for a stereo pair--and the complications it adds to an audio or home-theater setup?

The version I tested consisted of two fiber-optic Cobra cables that each attach to a transmitter and receiver, they plug into your components. Since each cigarette-pack-size unit get power from its own transformer, you may need an extra power strip to hold all four.

I tested some CDs, and the music sounded just right. When I substituted heavily shielded premium cable by Esoteric, they sounded the same.

Much ado about nothing? Not exactly. While my conventional cable was a one-meter length, the Mongoose used six-meter cables. Ordinary interconnect cables lose signal strength and introduce noise at that length. Simply by sounding as good as a short premium cable, the Mongoose worked a minor miracle.

Still, long interconnect (as opposed to speaker) cables are rarely used in most most systems. For short runs, the difference between cheap cable and shielded premium cable is greater than that between premium cable and the Mongoose. So the Mongoose performs a neat trick--but one that's needed only if you're running interconnects between rooms.--Mark Fleischmann

Popular Science Feb. '95