These are screen captures of video feedback. Video feedback happens when a video camera is pointed at the screen of a television that is displaying what the video camera is seeing. This is similar to audio feedback, which happens when a microphone and its speaker come too close. These still pictures only feebly capture the wide range of spinning, flashing and rippling shapes that you can make this way.

The first two rows are just the camera and the tv. The second and third rows I experimented with a small piece of paper stuck to the screen, and then with a candle reflection on the screen. The last two rows were made on a brand new big screen tv. The quality of the tv makes a big difference- the better quality, the less noise in the system, which makes for less feedback. Note in some of the last images, you can actually make out a window and a checkered curtain being picked up by the camera, behind the tv.