My wife recently got a little solar-powered prism for our backyard window that starts rotating once it’s charged up with enough sunlight. This has given sunny mornings an extra little burst of magic with little rainbows streaming around the room, one of which I managed to capture as it dashed right next to one of the can lights:

The contrasts proved, uh, illuminating: artificial vs. natural light, smooth vs. textured, circular vs. streaked.