Friday, July 20, 2007

White Balance

Light has a wide variance in color temperature which will affect the overall color tint of a digital image. Digital cameras provide adjustability to compensate for variation in the color of light and this function is referred to as "White Balance".

Many cameras today provide several “Preset” white balance such as daylight, cloudy, tungsten, fluorescent, etc. The fluorescent setting on digital cameras is normally meant to be used with the type of fluorescent bulbs found in offices and commercial buildings. Those bulbs typically have a slightly yellowish or greenish color cast. The daylight balanced bulbs which we sell are daylight balanced bulbs. Daylight bulbs normally don't require color correction. The standard white balance setting for daylight balanced fluorescent bulbs is Auto White Balance (typically marked as AWB). Should you find that you are getting a color cast with AWB, and then you could try the Daylight setting.

Using a "preset" white balance may not reproduce perfect color but will always be consistent when using a specific light source. A consistent color shift can be corrected with software, and once you get the correction parameters set, you can use this adjustment on every image and get consistent results.

"Auto" white balance or AWB can cause random color shift depending on the subject, and this color shift will require adjusting color balance with software.

"Custom" white balance setting is the best solution with your studio setup. The procedure for using Custom white balance varies depending on the specific model of camera, but it normally entails shooting a test picture with a gray or white background, then calibrating the camera to use that picture as a reference for color correction. This option will provide near-perfect color reproduction when using artificial lighting. Study your camera manual for procedures on setting "custom" white balance.