Back in January 2015 I was thrilled to be able to finally light paint underwater with my newly acquired Gopro Hero 4 Black. I lost it in 2017 but I did manage to create some cool stuff with it that I'm still proud of today.
I used to wait for torrential rain and went to the local park with the gopro, a few waterproof light painting tools that I had made, a UV laser, steel wool, rubber boots and a rain suit. Why while raining? because I wanted to use the chaos of the ripples on the water to diffract in cool ways what I was doing above water. Also I had previously discovered that the water in this park reacted a vivid green with the UV laser I was using especially after a rainy day. Perhaps UV reactive fungal spores? I do know some spots in this park that are rich in UV reactive mushrooms. I found it fascinating. What I did was I put the gopro underwater set in timelapse mode at 30 second exposures and then I waved lights or steel wool above water and/or strategically aimed the UV light to hit close to the camera but not in the lens. In one of these I also used a thermal blanket on the water surface.
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