Physics of Sports and the Arts

The following photographs were taken by students enrolled in the science class "Physics of Sports and the Arts."

Sound Trigger
Each of these images was taken using a sound trigger. A sound trigger can be used whenever an event is accompanied by a significant sound. The digital camera is used in the bulb mode so that the shutter is held open. This is done in a completely dark room. The light is from a flash unit with a thyristor which gives a very short burst of light. A longer burst of light will result in a blurred image. The flash unit is triggered using a sound trigger. The sound from the event travels at the speed of sound to the sound trigger. The trigger starts the flash. The thyristor turns off the flash unit. To adjust the delay, the sound trigger can be moved closer or farther from the sound source.

For more information on high speed photography click here:
http://courses.ncssm.edu/hsi/pacsci/index.html

To see a close-up of the photos, simply click on the individual picture.

Special thanks to:

The DeKalb Education Foundation
for providing the funds to purchase the Nikon 995 digital camera. Unlike most digital cameras, the Nikon 995 has a bulb setting to allow the shutter to be held open while the event takes place.
Jim Womack and Womack Photography
for the donation of the Vivitar 283 Flash units. Unlike many flash units the Vivitar 283 has a thyristor which allows the duration of the light flash to be shortened. A very short flash of light is necessary to ensure a clear image.

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Last updated 3/5/02