Roger Pellegrini writes:
Wanted to send you a note about a second video I did, also starring the wind-up toy robot and synths [featured in the first Robotmakers vid], but with some content that could be of interest to Makers. Back in the mid-1980’s, I dug a couple of first generation laserdisc players out of the trash, and took them apart. The laser in these early players was an 8″ he-ne tube, considerably more powerful than the tiny laser diodes in modern CD/DVD players. Also of interest were the orthogonal mirrors, mounted on galvanometers that were used to align the laser. By salvaging the power supply and combining these elements, you can cobble together a home laserium effect that works surprisingly well. If you power the x and y orthogonal mirror elements with the left and right channels of a stereo amplifier, you get a working oscilloscope. Of course, with synthesizers at hand, you can manipulate the projected imagery in interesting ways and it was bright enough to use on stage with a band I played in.
In the new Robotmakers video, there are scenes (e.g. 30 seconds into the video) where I used the laser to create an interesting special effect seen in various sci-fi movies and in The Who’s “Won’t Get Fooled Again” from “The Kid’s are Alright” film.
– First, create a circular image using the laser by feeding one channel (ie mirror) a simple waveform and the other channel a delayed version of the same waveform. For example, a sine and a 90 degree out of phase sine powering the x and y mirrors will produce a circle. The resulting light path will create a cone in space.
– Second, create fog. Not having a fog machine handy, I used a household steamer to spray steam from off-screen into the path of the laser.
– Place your actor (or Personal Apprentice) in the cone walking away from the source towards a camera placed within the cone, facing the laser source.
– Turn off lights, and enjoy! The actor will appear to be walking within a tunnel of light whose intensity varies according to the density of steam or fog.
The Modern Android Cybernaut – Robot, Lasers & Citizen Kane – Link
- Bot rock with the Robotmakers – Link