Light painting at school

Today was the "Lesmarathon" at school, where the oldest children spend an entire day at school. They are sponsored: for every hour they stay, they'll get some money to be used for their school camp outing later this year. I was helping, creating bristlebots in the morning with all 24 children and at night I did light painting workshops. Great fun and we got some great results, but I can't show any of the images with the children on there. So here's a shot I did to prepare for the workshops, to get to the right camera settings. In this shot, it was completely dark and I light painted the chairs and then used a green flashlight to paint above the chairs.