Philips Hue LEDs take smart bulbs to a whole new level
converted most of his home to LED lighting. I didn't have any fancy plumen bulbs in mine, so as part of my renovation, I got rid of every incandescent and compact fluorescent in my entire house. Inexpensive LED bulbs like the Cree that Matt used and the flat, funny-looking flat Philips bulbs that I used in some ways work like the old fluorescents did; they had ionized mercury vapor-emitting ultraviolet light, which excited a phosphor coating to glow white. That's what's happening in the white LEDs as well, but without the mercury. Instead, the LED emits the light that excites the phosphor. It's not perfect; the phosphors are mixed and tuned to be as close as possible to the incandescent light we all love, but the color rendering index (CRI) is not quite there.