i came downstairs this morning after the sun had risen but before the shutters were open; the sun was shining in through a tiny gap in the shutters and hitting the prism perfectly, and i just stood there staring at it. i went to get my phone after a bit and just managed to get a photo and video (in replies: the prism was moving so the rainbows were too) before it went. it didn't last long, but it was actual magic on the walls.