By photographing a gray card reference for each lighting situation, you'll be able to achieve a proper white balance for all of your pictures. The gray card reference picture can be used with software to balance the color casts that various lighting conditions produce with all digital cameras.
Features:
Spectrally neutral--reflects all colors through the spectrum equally.
Maintains its spectral neutrality under all reasonable temperature and environmental conditions.
Rugged--waterproof and scratchproof (color goes all the way through, not just a coating on top).
Each card is individually measured with a precision spectrophotometer to certify that it meets or exceeds stringent specifications.
Designed for low reflectivity, with a highly reflective sticker so that maximum TrueBlack Blackpoint level may be achieved by observing for maximum glare point and then backing the angle down.
Can be used to set white balance reference, black point, and white point.
