Black fabric or perforated metal flag mounted above a light source to prevent unwanted spill light from bouncing upward.
Technical Details
Top flags are made of black molton, duvetyn, or perforated metal on an aluminum frame. They are mounted via C-stand arms or directly to the fixture using barndoor mounts. Flexible variants (Flex Flag) use a bendable frame for curved light cuts. For HMI lights from 2.5 kW upwards, heat-resistant metal versions are standard, as temperatures can reach up to 300°C. The distance to the light source is typically 30-90 cm, depending on the desired sharpness of the cut.
History & Development
Top flags originated in the 1920s with the development of the first studio spotlights. Hollywood DP George Folsey developed the "Four-Flag System" in 1935 for precise light shaping. In the 1960s, Italian film studios introduced perforated metal versions used with hot tungsten lights. Digital cinematography from 2000 onwards enabled more precise light measurement, leading to the development of more subtle flag techniques.
Practical Use in Film
In portraits, the top flag prevents unwanted illumination of the background's upper edge, as seen in "Blade Runner 2049" (2017) during interrogation scenes. In dialogue scenes, it limits the key light to face level, creating natural shadow fall-off. Cinematographer Roger Deakins systematically uses top flags for window light simulation to create realistic room lighting. In outdoor night scenes, they prevent light reflections on fog or smoke above the actors.
Comparison & Alternatives
Unlike barndoors, top flags offer softer light transitions due to their greater distance from the light source. Cutters (narrow flags) create sharper cut-off edges, while scrims reduce light intensity without changing direction. Modern LED panels with integrated honeycomb grids partially replace external flags. French flags (small attachments directly in front of the lens) solve similar problems at extreme light angles, but with a different cutting characteristic.