Here's the resulting video, 10 seconds per frame displayed at 30 frames per second for a 300x speedup.
It never quite focused right. If I were to try this again (in 7 years, with a rpi version 9 and whatever upgraded camera comes with it then) I'd try harder to seal off the light leaks from the box. I wasn't on my usual network and couldn't log into the rpi to get images as it went so I had to open the box now and then to reposition and track the sun.
