Adric from QueLab Hackerspace in Albuquerque, tested a photosensitive plate in a pinhole camera, and left it in place for an exposure that lasted weeks. This is the same photosensitive plate that they sell at Takach Press, and they use the same plate to make etching prints at Remarque Print Workshop.
The photosensitive plate
after it's been washed and "developed,"
after weeks of exposure
(it may not be pretty, but it worked!)
The pinhole camera
Adric also sent me this YouTube link, to an animation collaboration between Salvador Dali and Walt Disney, now set to the music of Pink Floyd.