In television, film, stage, or photographic lighting, a fill light (often simply fill) may be used to reduce the contrast of a scene and provide some illumination for the areas of the image that are in shadow. A common lighting setup places the fill light on the lens axis, roughly perpendicular to the key light.
The fill light is often softer and, by definition, less intense than the key light. The ratio between light and shadow depends on the desired effect. For example, a fill light that is a small fraction of the power of the key light will produce very high-contrast or low-key lighting, while filling with half or more of the key light power will produce a high key, low-contrast tone.
In cases where the fill light is desired to be darker than what is available without artificial means, a flag or frame may be used to block ambient light and thereby provide what is called negative fill.
An alternative to using a direct light source as a fill is to re-direct or "bounce" the key light towards the subject by using a reflector.
Famous quotes containing the words fill and/or light:
“What seems to me the highest and the most difficult achievement of Art is not to make us laugh or cry, or to rouse our lust or our anger, but to do as nature does—that is, fill us with wonderment.”
—Gustave Flaubert (1821–1880)
“The food of thy soul is light and space; feed it then on light and space. But the food of thy body is champagne and oysters; feed it then on champagne and oysters; and so shall it merit a joyful resurrection, if there is any to be.”
—Herman Melville (1819–1891)