Photographer Mike Rosinski created this amazing image showing light trails from both fireflies and stars by stacking over 370 photos shot over 2 hours from his backyard in Hartland, Michigan. He used a Canon T1i and 15-85mm lens at 15mm with 20 second exposures. The stacking was done with StarStaX, a free program geared towards star trail photography. You can find more about Mike Rosinski’s work (prints, licensing fees, etc) by contacting him here.
Image credit: Photograph by Mike Rosinski and used with permission