White Balance

White balance is the process of calibrating image data so that white objects in a scene render as neutral white in the recorded image, regardless of the color temperature of the light illuminating them. The human visual system performs white balance automatically — we perceive a sheet of paper as white whether viewed under tungsten light (warm), fluorescent (cool-green) or daylight (neutral). Camera sensors do not adapt this way; without white balance correction, an interior shot under tungsten lighting captured with a daylight white balance setting appears strongly orange. White balance is typically set in three ways: by selecting a preset (daylight 5600K, tungsten 3200K, fluorescent 4000K), by using a custom Kelvin value, or by sampling a known-white reference like a gray card or X-Rite color chart on set. Most modern cameras also offer auto white balance, used cautiously in narrative production because it shifts between takes. In post-production, white balance can be re-adjusted within the latitude of the original capture — RAW formats preserve all sensor data and permit large white balance corrections without quality loss, while compressed formats baked at the camera's setting are limited. Color correction routinely begins with verifying or correcting white balance on every clip as the foundation for subsequent grading. Reference: most color grading textbooks (Hullfish, Van Hurkman) discuss white balance methodology in depth.