What technique is used to achieve a silhouette effect in photography?

To achieve a silhouette effect in photography, backlighting the subject is the key technique. When a light source, such as the sun, is positioned behind the subject, it creates a stark contrast between the brightly lit background and the darkened figure of the subject. This contrast results in the subject appearing as a dark outline against the lighter background, thus forming a silhouette.

The use of backlighting is crucial because it ensures that the subject is not directly illuminated by the light source. Instead, the light highlights the edges of the subject, allowing for the distinctive shape to be captured while the inner details remain obscured.

In contrast, using a flash would typically illuminate the subject from the front, resulting in a well-lit image rather than a silhouette. Increasing the aperture size would allow more light to enter the camera, which could expose details of the subject instead of creating a dark outline. Similarly, employing a low-angle shot does not inherently create a silhouette effect; it merely changes the perspective from which the subject is photographed and does not directly impact the lighting contrast required for a silhouette. Thus, backlighting is the definitive method to achieve that classic silhouette look in photography.