Mike Black, a Wall-based teacher and photographer, caught this photo Wednesday of a naturally occurring sun halo. The optical phenomenon is produced by ice crystals creating colored or white arcs and spots in the sky. Light is reflected and refracted by the ice crystals in the upper atmosphere and may split into colors because of dispersion. The crystals behave like prisms and mirrors, refracting and reflecting sunlight between their faces, sending shafts of light in particular directions.