September 2000

LEDs Light the Future

Continued from page 4

By Neil Savage

An Eerie Glow

But if LEDs are to capture a large share of the illumination market, they will have to produce light with the right tone. As anyone who has ever taken an indoor picture with outdoor film knows, incandescent light has a strong yellow cast, and designers say it has a warm feel. White phosphor LEDs, on the other hand, emit a distinctly bluish glow. "If you're trying to illuminate a red object with a white LED that only has blue and yellow in the spectrum, you're not going to get a very nice-looking red," warns Kathryn Conway of the Lighting Research Center at Rensselaer Polytechnic Institute. That can be a problem with human skin, for instance, which looks unnatural under light that doesn't approximate daylight. Renowned New York lighting designer Howard Brandston points out: "You don't want someone to wake up in the morning and look in the mirror and say, 'Egads! I could audition for "The Addams Family" without makeup.'"

But the technology will definitely keep improving, since the payoff is large-in part because with LEDs, you'll be able to turn a dial to get lighting with just the right feel for the situation at hand. Brett Andersen, a senior designer at Focus Lighting, a New York-based lighting design firm, envisions a day when people will be able to set the color and brightness of the light in their homes according to their moods. This kind of control will make the old-fashioned dimmer switch a primitive tool for creating ambience. Beyond that, LEDs offer new possibilities that raise more fundamental questions about how people think about lighting, says Chipalkatti of Osram Sylvania. "How would things look if the building itself was a light fixture?" he asks. "You could have your floor or your ceiling light up."

In the offices of Color Kinetics, software writer Mike Blackwell sits on the chameleon couch and demonstrates the program he's developed for lighting designers to create effects with the company's lights. He sets a row of lamps to run through the spectrum, repeating the cycle every 10 seconds. Then he adds a white pulse that moves down the row once a second. The effect is jarring, reminiscent of the psychedelic light shows of the 1960s. It also suggests artifacts of another era: those desktop-published newsletters of the mid-1980s, brimming with clashing fonts. But if lighting designers are right, more sophisticated users will be able to create subtler effects or repaint their walls with light. And perhaps the incandescent bulb will join an earlier lighting standard, the candle, as a quaint accent for special occasions, while our days and nights are lighted in the glow of tiny chips.