Predawn Sky

Altocumulus undulatus clouds seem to radiate from the point where the sun would rise on the morning of Wednesday, May 11, 2011. The photo was shot at 5:15 AM and sunrise occurred at 5:50 AM. The house where the glow of lights is seen at center is located on the north side of Boyson Road in Marion, Iowa between Timber Oak Court and Alburnett Road. The prefix "alto" denotes clouds of middle-level altitude--approximately 6,500-16,500 feet. This image was captured using a 3-second exposure at f/10, an ISO of 500 and a focal length of 18mm.