Light (both natural and otherwise) is an essential tool in photography - here's a gallery dedicated to light use in photos, including low-light photography, black and white available light photos, night and morning photos.
Cass & Mindy
© Michelle CampbellTired Flower Girl
© Michelle CampbellPractice Makes Perfect
© Michelle CampbellSolitude
© Dennis Begnoche JrWondering
© Debbi Brucker