I was shooting night shots on a beach in Cape May, NJ when I suddenly saw tiny specs of light blue spots light op in the sand when i walked and dragged my feet. It only lights up when triggered by touch. You don't know where it is, the concentration was not big here, and it only lights up a few times when touched. So I had to guess where it was and the run my hands through the sand while shooting. This is shot with a Sony A7s, iso 16000, f2, 1/3sec wit a 55 mm