The Challenge ..Capture a water drop—the moment after or during impact. The "water" need not be actual water (any liquid is fine that works), and the impact need not be generated in water (in other words, feel free to capture a water dropping on any sort of solid).
I shot this with a Canon Rebel T1i with a 100MM canon macro lens at f/13 iso 200. I triggered 2 flashes to fire after a delay when the water drop breaks a beam, using a custom controller I built for doing long exposure astrophotography called chonocam. What you see is 2 drops colliding. The first drop creates a little up splash and if you time your second drop PERFECTLY they will impact each other and viola. I added some red food coloring to the drops for contrast. The pool is just a Pyrex dish with some black garbage bag plastic for lining