The camera shutter is triggered by ambient radiation.
The monochrome squares/image densities are determined by the duration between events.
La Bastille: July 17, 2015, 13:02:52 - 13:03:52
One minute's consecutive events at La Bastille on the afternoon of July 17, 2015. Sheet size: 13" x 38"
La Bastille: July 17, 2015, 13:02:52 - 7:06:28
Sheet size: 24" x 36"
La Bastille: July 17, 2015, 14:08:28 - 14:14:48
Sheet size: 24" x 40"
La Bastille: July 17, 2015, 12:47:54 - 12:50:13
Density reflects duration between events. Sheet size: 13" x 19"
La Bastille: July 17, 2015, 12:47:54 - 12:55:31
Density reflects duration between events. Sheet size: 24" x 31"