This was made whilst listening to Interstellar Overdrive, twice.
The trick with video feedback is to ride the brightness knob to keep a fine balance between the image going away into blackness or blooming into whiteness. You want to be in the gray area, in middlespace, where the interesting things happen. Here’s a pretty good 20 minute stretch riding that fine line.
For more videos and info: lightherder.blogspot.com