Creating composite images from two photographs-one of the moon and the other of a landscape or wildlife scene-is a time-honored (although sometimes controversial) nature photography technique. During the film days, photographers would often dupe a moon into their images by exposing a single piece of film twice, or by physically combining two pieces of slide film into one mount (creating what was known as a slide sandwich). Today, digital cameras offer a more elegant solution: multiple exposures can be combined on the computer to create seamless images.

Moon composites are easiest to create when the backgrounds of the composite images are identical. Let's start with a very simple example: a full eclipse of the moon, photographed in a series of five images of the moon entering and exiting the eclipse, combined to show a sequence of the moon's transition. Because it was a dark night, each exposure has the same, completely black background.

ABOVE: Five images taken during a full eclipse of the moon.