VPS member, Dan Feighery, has offered to give a short explanation and demonstration of a shutter triggering device called the SHUTTERBEAM. The Shutterbeam provides a triggering signal to the camera's remote cable release. based on the interruption of an Infrared beam or a detection of a sound.

For example, his shot of a hummingbird in flight, that some may have seen last year, and the image of the falling dice (in a fall edition of Focal Points) were made by interrupting one or more infrared beams. His images of a bursting balloon were made by having the sound of the bursting balloon trigger a flash. The delay between the "explosion" of the balloon and the instant the image was captured was adjusted by placing the sensor at various distances from the sound source. Since sound travels at about 1088 ft/sec (sea level in dry air at 32 degrees), he approximated the sound pulse moving at about 1 foot each millisecond (1/1000th sec). so by placing the sensor at say 2 foot from the balloon, the flash goes off in about 2/1000 of a second; capturing the image before the pieces are completely gone. If you try to capture the image by triggering the camera (rather than the flash) it is unlikely that the you will see any of the balloon.  That is because of the lag between the instant the shutter release is pressed and when the image is taken, is probably too long.  For example, with a Nikon F-5, there is about a 43 millisecond delay for the shutter to react, and the pieces of the balloon are long since gone.  Using a Canon in "RS mode" provides about an 8ms delay since there is no mirror to move, etc.

A web search for SHUTTERBEAM will show more examples.

For the May forum, Dan will set up the shutter beam and reflector to demonstrate how you trigger a camera with beam interruption, and also demonstrate the sound trigger.