I recently converted my home-made Meccano 2-axis webcam mount into a laser mount. The system is made of an Arduino board that sends timed signals to two servo motors, mounted at right angles to each other. This gives a crude x&y pointer, which I can use to 'draw' patterns on any surface. My desk is illuminated by many vertical sweeps of a 1mW red laser. A Leica C-LUX1 was used in 60 second extended exposure mode.
This one is a visualisation of 'Brownian motion'. Brownian motion is analogous to a 'random walk'. The walk is not truly random because the same pattern will be generated every time the system is reset.
This image is a visualisation of the morphology of the 2-axis mount for the laser. It's clear from this image that the unit is more stable when making vertical sweeps than when it makes horizontal sweeps. The increment I used for moving the laser also affects the quality of the scan.
Now I'm telling the laser to point along 8 different directions. The unsteadiness mentioned in the previous image is seen along any direction that has a horizontal component. The increment used in this picture is small, so overall the quality of the line is smoother.
My desk is illuminated by an expanding 8 sided spiral. The laser gives a clue as to the type of material it hits,for example the translucent plastic of my computer versus the opaque wood of my desk.
In a future post: I've added a microcontroller switch to the laser, enabling me to 'pick up the pen' as it were. Super-sneaky sneak preview: Here's a random dot pattern, playing across one of my clay sculptures: