DR GARY SETTLES / SCIENCE PHOTO LIBRARY DR GARY SETTLES / SCIENCE PHOTO LIBRARY
Lightbulbs. Schlieren photograph comparing energy release between three different types of lightbulb. Each bulb produces approximately 1600 lumens of light. The ordinary incandescent filament bulb (far right) is inefficient and requires 100 Watts of power. The compact fluorescent bulb (centre) draws only 23 Watts, while the LED bulb (left) is rated at only 13 Watts. Both the incandescent and the fluorescent bulbs produce significant buoyant thermal convection plumes that are clearly seen under schlieren observation. The LED sheds some waste heat as well, but not by natural convection, it has an internal air-moving device. It also appears not to provide as much illumination as the other two however it is a spotlight that is pointing upwards.
Model release not required. Property release not required.