Physiogram Fun For All March 26th @ 7 pm. Summary: Technically a physiogram is a long exposure photograph of moving light.

There are many ways to make the light move. You can hang the light on a swinging pendulum you can put the light on a machine that moves the light or you can even swing the camera to make it look like the light is moving. However you move the light the resulting image is a record of the path the light took during its journey.

The mathematical term for these images are hyptotrochoid patterns. They are the same patterns that you get when playing with spirographs.

Materials:

• Camera 35milimeter SLR or digital with a bulb setting Bulb
• Cable release Lens card
• Theater gels of different colors
• String or monofilament
• LED Flashlight
• Eye hooks
• Dark room Mirror
• Tripod
• Foam Core
• Exacto blade
• Tape

Procedure:

• Mount light to pendulum
• Make camera placement template
• Install cable release
• Focus Camera
• Set exposure to bulb settling
• Turn-on swinging light
• Place card over lens
• Turn off room lights
• Swing light
• Open shutter
• Remove card
• Wait for between 30 seconds and 5 minutes
• Replace card over lens
• Close shutter.

Background:

1. http://www.barrypearson.co.uk/articles/physiograms/references.htm
2. http://www.flickr.com/photos/tags/physiogram/interesting/ http://en.wikipedia.org/wiki/Harmonograph
3. http://web.njit.edu/~jcl7/pastimes/pendulum/index.html