Bounce Board

Bounce Board

noun | Camera & Optics

A flat, reflective panel used to redirect light from a primary source -- the sun, an HMI, a window -- onto a subject from a different direction. Bouncing light off a large white or silver surface dramatically increases the effective size of the light source, producing soft, diffuse illumination. The bounce board is one of the simplest, most portable, and most effective light-shaping tools in cinematography, equally useful on a zero-budget documentary and a major studio production.

Quick Reference

The Explanation: How & Why

The fundamental principle behind the bounce board is that the effective size of a light source -- not its wattage -- determines the softness of the light it produces. A small, direct light source creates hard, sharp-edged shadows. A small source bounced off a large white surface becomes, effectively, a large source (the entire reflective surface) -- and a large source produces soft, gradual shadows.

When a hard directional source such as the sun or an undiffused HMI is bounced off a 4-foot by 4-foot white foam board, the board becomes a 16-square-foot soft source. The shadows produced by this bounced light have soft, gradual transitions rather than the sharp edges of the original source. The subject is lit with a quality close to that of a large softbox or overcast sky, using nothing more than an inexpensive reflective panel.

Bounce boards come in several surface types, each producing different light qualities:

White foam board (polystyrene, poly board): The most common and versatile bounce surface. Produces soft, neutral-coloured, diffuse light. Available in 2x4, 4x4, and 4x8-foot sheets from hardware stores. Industry-standard choice for soft fill and key bounces.

Silver (bead board, reflective mylar): Reflects more light than white foam and introduces less diffusion -- the bounced light is brighter and slightly harder. Used when maximum output is needed or when the softer quality of white bounce is insufficient.

Gold reflector: Adds warm colour to the bounced light -- used to simulate warm afternoon sun fill or to add warmth in cold exterior environments.

Grifflon (silver-and-white reversible fabric): A collapsible grip reflector available in multiple sizes, silver on one side for hard/bright bounce, white on the other for soft/neutral bounce.

The position of the bounce board relative to both the source and the subject determines the intensity and angle of the bounced light. Moving the board closer to the source increases the intensity of the bounce; moving it closer to the subject increases the effective source size and softens the light further.

Historical Context & Origin

Reflective boards have been used to redirect natural light onto subjects since the earliest days of photography. Victorian portrait photographers used white-painted walls and ceiling panels to redirect window light onto subjects in dark studio spaces. Cinema adopted similar techniques as soon as filming moved outdoors and natural light needed to be shaped. White bedsheets, muslin, and later purpose-made aluminium reflector boards became standard grip equipment in Hollywood productions of the 1920s and 1930s. The development of collapsible, foldable reflectors in the 1970s and 1980s -- the Lastolite and Photoflex reflector systems -- made portable bounce boards a standard part of the solo cinematographer's kit. The contemporary foam board, available in large sheets from builders' merchants for a few dollars, democratised the bounce board completely: any production at any budget can deploy multiple large soft sources for the cost of a sheet of building insulation.

How It's Used in Practice

Scenario 1 -- Exterior Day (Grip / DP): An interview is set up outdoors on a bright day. The subject is positioned with the sun behind them as a natural backlight -- warm, glowing, flattering. But the face is now in shadow and severely underexposed. The grip holds a 4x4 white foam board to the side and slightly above the subject, angled to catch the direct sun and redirect it onto the subject's face. The bounced fill opens the face by 2 stops without adding any artificial light. The subject now has a warm backlight and a soft, natural-looking fill from the bounce.

Scenario 2 -- Interior Low Budget (DP): Shooting a dialogue scene in a small apartment with a single window as the key source, the DP has no fill light instruments available. A grip holds a 2x4 foam board on the shadow side of each subject, angling it to catch light spilling from the window and redirect it as fill. The bounce provides a soft, window-coloured fill at a 3:1 ratio relative to the direct window key. The scene is lit to a professional standard with no electrical instruments at all.

Scenario 3 -- Controlled Studio (Gaffer): On a studio stage, the gaffer uses a 4x8 poly board as a bounce surface for a 2K HMI. The HMI points directly at the board from 8 feet away; the board redirects the light toward the subject. The resulting bounced source is approximately 4 feet wide and 8 feet tall -- a very large, extremely soft key source. The gaffer adjusts the board's angle to control the key direction and raises or lowers the board's position to adjust the key height.

Usage Examples in Sentences

"Hold the bounce just outside frame to camera right -- angle it until the shadow side opens up."

"A 4x4 poly board in full sun gives you as much output as a 1.2K HMI and it is completely free of noise, heat, and cable."

"The whole exterior was lit with just a bounce board redirecting the afternoon sun -- no instruments on that location."

"Silver side for more output; white side for softer quality. Flip it depending on what the shot needs."

Common Confusions & Misuse

Bounce Board vs. Flag: A bounce board reflects light toward the subject. A flag is a black, non-reflective panel used to block light from reaching certain areas or the camera lens. Both are flat panels on similar rigging hardware and may be confused when listed in a lighting plan. The critical difference is functional: bounce adds light; flag subtracts it. Both are managed by the grip department and are standard equipment on the grip cart.

Bounce Board vs. Diffusion Frame: A diffusion frame is placed between a light source and the subject, with diffusion material stretched across it, to soften the light as it passes through. A bounce board redirects the light by reflection rather than transmission. Both soften light by increasing the effective source size, but through opposite mechanisms -- transmission versus reflection. Diffusion frames reduce light output by blocking a portion of the direct beam; bounce boards can increase the effective light reaching the subject (by redirecting what would otherwise not illuminate it) while also softening it.

Variations by Context

Related Terms

• Diffusion -- An alternative method for softening light through transmission rather than reflection
• Key Light -- Bounce boards are often used as large soft key sources by redirecting a harder primary source
• Available Light -- Bounce boards are the primary tool for shaping available light without adding instruments
• Ambient Light -- Bounce boards increase local ambient levels by redistributing existing light
• Gaffer / Grip -- Both departments use bounce boards; gaffers direct the lighting intent, grips position the boards

See Also / Tools

The Lighting Power Calculator is relevant when the bounce board setup is supplemented by artificial sources -- calculating total power draw ensures circuits are not overloaded when instruments are added alongside bounce-based setups.