The short answer is that when you open up the shutter of your camera and draw an image with a light source, the camera records all light in front of it as if it happened at once. It’s recording the light without regard to what time the light comes in, just like a piece of paper records a pencil’s lead, but not at what time it was scribed there.
An illustration of How Light Graffiti Works:
This animated GIF should show things somewhat more visually (as I attempted to do with this glowing display). My camera was set to take several shots one after another at a pre-determined exposure time. In this animated GIF each frame is actually the product of it and every previous frame added together with GIMP (how the double-exposures were made and the animation). The end product is equivalent to what happens in a camera when the shutter is opened and it captures all of the light going in.
To put it another way, light graffiti transforms something – gathering light from a source or sources – that takes place in a finite amount of time into something represented as a single image. As if it took place in an instant.
Below are some examples of graffiti that I’ve done. I’m always doing new experiments with this and all kinds of other things, so be sure to subscribe (upper right on page) to not miss anything!
Information on Pictures
More Background Information
- GIMP technique for making GIF animations
- GIMP technique for making a double-exposure shot
- Servo Light Graffiti machine – what I used to make the face in the illustration
- Four Dimensional Space Wikipedia Article
- My Introduction to light graffiti techniques
*Taking this thought process a bit further, traditional photos resolve an instant in time that takes place in 3 dimensions into 2. Light graffiti, since it’s recording something that happens over time, regarded as the fourth dimension, actually resolves this event from 4 dimensions into 2. Pretty crazy.