You can great some pretty dramatic effects with at a $5 red laser pointer and a digital camera. I started with the red laser from the back of a DVD player (the “digital optical out” on modern CD and DVD players). I was trying to fix a DVD player and saw this light shooting out the back (the lens cover was missing). It normally couples into a fiber link to the audio amp.
I pressed the camera lens right up to the back of the player. It was extremely sensitive to angle and lateral shifts because the laser is highlighting irregularities in the optical lens array (scattering, reflections, imperfections in the lenses and coatings). The effect became more pronounced when the camera was in 3x optical zoom. And what I saw told me “Don’t Panic!”
Then I tried a cheap laser pointer pen. It created a wild array of effects when shot right into the digital camera. The light source is pure monochromatic red:
So, the cool part is that these colors emerge from in-camera artifacts (I suspect flaring from the lens array and saturation of the CCD Imager to white at the core).
I borrowed more powerful green and red laser pointers, and found a variety of textures were possible as well:
I find the emergent colors and forms to be beguiling and fascinating. There is no subject being photographed. It’s just a single point source of light and a camera. (Here’s my laser art gallery)