Combining all three additive primaries at 100% intensity produces white light. For example, Green + Red = Yellow, Red + Blue = Magenta, and Blue + Green = Cyan.Īdditive Primaries Red, Green, and Blue light. The most commonly used additive color model is RGB (red, green, blue), which is used by computer monitors to produce their display and scanners and digital cameras to capture images.Īdditive Color Mixture Mixing of the three primary color lights (Red, Green and Blue) to obtain colors. This allows the visual system to adjust its sensitivity to different lighting conditions.Īdditive Color The sum of primary colors to produce a multitude of colors. This is the same equation used to calculate density in graphic arts and photography applications.Īchromatic Color Light without color, which produces a neutral white, gray, or black color that does not have a hue.Īdaptation The ability of the eye to adjust to different light sources or light levels. Mathematically, absorbance is calculated A = log10(1/T) where T is transmittance, expressed as a decimal from 0 to 1 (for example, 0.5R is 50%R). When calibrating a spectrophotometer, often a white ceramic plaque is measured and used as the absolute white reference.Ībsorb (Absorption) Dissipation of the energy of electromagnetic waves into other forms (e.g., heat) as a result of its interaction with matter a decrease in directional transmittance of incident radiation, resulting in a modification or conversion of the absorbed energy.Ībsorbance “Light-stopping ability.” The higher the value, the more light the sample absorbs. In practice, a solid white with known spectral reflectance data that is used as the reference white for all measurements of absolute reflectance. Absolute colorimetric is most commonly used for proofing and is rarely used by photographers.Ībsolute White In theory, a material that perfectly reflects all light energy at every visible wavelength. This method preserves the white point, which may sound appealing, but may actually result in image color shifts. A positive a* value indicates redness and a negative a* value indicates greenness.Ībsolute Colorimetric Rendering Intent A rendering intent that preserves in-gamut colors and clips those that are out-of-gamut. Out of Production Products - Find Your UpgradeĪ B C D E F G H I J K L M N O P Q R S T U V W X Y Z Back To TopĪ* Red - green coordinate in CIE L*a*b* color space.