A
silhouette is the outline of a solid figure as cast by its
shadow. It was first documented by
Etienne de Silhouette. Silhouettes were then popularized by the
Victorians who used them as
portraits, cutting the outline of a person in black and then mounting it onto a bright background. They are also popular among
kindergarten teachers who are teaching the kids to use
safety scissors.
(Mother's Day cards with the outline of a child made with love)
Silhouettes are easy to produce in photographs by using backlighting. (Contre-jour). The shadow is on the camera side of the subject. Exposure is read off the bright background. The subject then is underexposed rendering it a silhouette.
The most important thing to do when taking this type of photo is to use a subject that is easily recognizable in shadow form. For example, good subjects are fishermen in a boat, trees at dusk, birds in the sky, surfers, buildings, weathervanes, etc., etc. Keep the composition simple to avoid cluttered backgrounds. The best time to capture these shots is when the sun is low in the sky. (sunrise or sunset). The sky is full of color and will make a perfect backdrop. Also, consider using colored filters to brighten or warm the background.