Tuesday, January 16, 2007
The Color Of Light
Master white balance for greater quality and control
But being casual about white balance and allowing the camera to determine it automatically can introduce unnecessary steps in your workflow. If the auto white balance produces slightly different colorcasts in the midst of a shooting session, the convenience of batch processing is reduced. In such situations, an accurate white balance becomes an issue not only of color accuracy, but also of workflow, as you have to interrupt it to fix individual images. It becomes clear that spending the few seconds it takes to properly set the white balance is more efficient than spending the minutes it will take to "fix" the image in software.
Using A Custom White Balance
I'm sometimes called to photograph subjects where color accuracy is crucial, such as food and fashion photography. This is achieved by creating a custom white balance with the help of a neutral white or gray surface, such as from a card or wall. Though the process will vary depending on camera design, a white balance measurement is made of a white or gray card that's illuminated by the same light source as your subject. Some cameras will record an image of the card and use that file to calculate the white balance. Others will take a reading off the surface of the card without recording an image. Whichever way the camera performs this process, the result provides the most precise measurement for white balance, resulting in accurate neutral tones and color.
Remember that when creating a custom white balance, it's not necessary for the camera to be in focus. All that's important is that the frame is filled by the card.
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