Like tiny crystal balls, water droplets can add a magical element to macro photographs. There are a number of moving parts to consider, but the basic concept is simple: a spherical droplet can act like a lens, refracting light from whatever is behind it. Getting good droplets can be problematic, as most surfaces will cause water to spread out rather than to bead up nicely. Using just plain water (no glycerine or other additives), one of the easiest foreground objects…