Leaf is a sculptural-looking creation made of two slim torqued aluminum parts. The arm is anchored by a solid disk containing a PC board; atop it are controls similar to the iPod's touch wheel. Slide your finger along the edge one way and the light glows golden; slide it the other way and the lamp emits the sort of pure white light that graphic designers need to run color tests. (In technical terms, it goes from 5500 to 2500 Calvin on the heat spectrum.) The dimmer works the same way; and a tap at the center, right on the backlit Herman Miller logo, turns the light on and off.
A grid of LEDs is fixed onto the head of the light. Heat--the number-one problem with using LED technology--is dissipated using a series of "chimneys," little holes that allow it to escape. A three-layer heat sink--backed by copper and aluminum--keeps the temperature below a manageable 60 degrees Celsius.