Flag
An opaque black panel placed to block light from reaching a specific area.
Measured in
cm
In depth
Flags are subtractive lighting: rather than adding illumination, they take it away, which is often the more precise control. Placed near the lens, a flag stops a rim light from flaring; placed beside a subject, it deepens the shadow side and increases the lighting ratio without touching a single power dial.
Examples in practice
A black flag placed just outside the frame on the shadow side deepens the ratio from 2:1 to 4:1 with no change in output.