Why should you avoid using flash when trying to create a silhouette?

When attempting to create a silhouette, the objective is to have the subject appear as a dark shape against a much brighter background. Using flash illuminates the subject, which contradicts this goal. The flash activates the camera's built-in lighting to brighten the subject, causing it to lose its dark outline and blending it with the surrounding colors instead of standing out starkly against the bright background.

A silhouette is best achieved by backlighting, where the light source is positioned behind the subject, allowing only the shape of the subject to be visible. Proper exposure settings must then be used to ensure the background remains well lit while the subject stays dark. Therefore, avoiding flash is key to maintaining the silhouette effect desired in photography.