Occasionally I want to convey a sense of high drama in a painting.
One of the ways to do that is to backlight the subject. Indicating a light source with light and shadow shows time of day, of course, and additionally it will also affect the mood of the entire work.
Backlighting can really make an object pop. These two paintings are in different mediums. The tulips are done in acrylic, and the amaryllis is a watercolor, but the use of backlighting in each adds to the drama of the overall look.