Physiograms

I have recently learnt that a selection of my light paintings are technically named 'physiograms'.

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, move it by hand, put the light on a machine that moves the light or 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.

Here are a few of my own examples: