Weird Line of the Three Mysteries

Photo date: December 28, 2015. Photographer: Mark Mahin.

The photo below was taken while photographing nothing but ordinary drops of pure, clean water falling against a dark featureless background. We see a line of ten of the strange objects I call orb crescents (shown also in this poster). There are three mysteries raised by this photo. First, why are these crescent shapes appearing? Second, why is one of the crescent shapes blue? Third, why do some of the crescent shapes seem to have little circles or symbols inside them (I can see what looks like the letter A or the number 4 inside two of the crescents).

I may note that whenever I get such crescent objects in my photos (as I have done 84 times) I never am using any special lighting that might explain such things. The lighting is almost entirely from the camera flash, which is pointing straight ahead at what is being photographed.  I never use anything like extra lighting from one side.