What is the function of flags and negative fill on a set?

• A. They hold backdrop in place.
• B. Flags block unwanted light and negative fill reduces light on the shadow side to control contrast and texture.
• C. They are used to measure exposure.
• D. They are used for color management.

Answer: (B)

In studio lighting, the main idea is to shape light precisely. Flags are opaque panels that sit between the light and the subject to block stray light and spill, which helps keep unwanted areas dark or prevents light from wrapping into places you don’t want it. Negative fill is a technique where you subtract light from the scene—often with a flag, black card, or other blocker on the shadow side—to reduce illumination there. That subtraction increases contrast and can reveal more texture and definition, giving the image a more dimensional look.

So flags and negative fill work together to control how light falls on the subject and to sculpt both the highlights and the shadows. For example, a flag can prevent light from hitting the background, keeping it clean, while negative fill on the subject’s shadow side deepens shadows and enhances texture. This is why the described function—blocking unwanted light and reducing light on the shadow side to control contrast and texture—is the best fit.