Cool photo. I put in a lot of practice taking blacklight photos way back when. I sorted my UV glass by brightness. In some of the less bright groups, I got some interesting colors. And then in those less bright groups, some shades photographed more brightly than others, so I bumped some of the marbles up to a brighter class or down to a less bright class, in order to get balanced pictures. I had lots of fun with that. Ended up with a "sun" tan on my left wrist from where I propped my long tube blacklight trying to get it into just the right position as I worked my camera with my right hand.