Subtractive color or subtractive color mixing predicts the spectral power distribution of light after it passes through successive layers of partially absorbing media. This idealized model is the essential principle of how dyes and pigments are used in color printing and photography, where the perception of color is elicited after white light passes through microscopic "stacks" of partially absorbing media allowing some wavelengths of light to reach the eye and not others, and also in painting, whether the colors are mixed or applied in successive layers.
Subtractive color mixingAn 1877 color photo by Louis Ducos du Hauron, a French pioneer of color photography. The overlapping subtractive yellow, cyan and red (magenta) image elements can be seen clearly along the edges of the image.
The subtractive color mixing model predicts the resultant spectral power distribution of light filtered through overlaid partially absorbing materials on a reflecting or transparent surface. Each layer partially absorbs some wavelengths of light from the illumination spectrum while letting others pass through, resulting in a colored appearance. The resultant spectral power distribution is predicted by sequentially taking the product of the spectral power distributions of the incoming light and transmissivity at each filter.[1]
PaintingEdit
The subtractive model also predicts the color resulting from a mixture of paints, or similar medium such as fabric dye, whether applied in layers or mixed together prior to application. In the case of paint mixed before application, incident light interacts with many different pigment particles at various depths inside the paint layer before emerging.[2] Art supply manufactures offer colors that successfully fill the roles of the subtractive primary colors magenta and cyan. For example, the phthalocyanine blues, which became available during the 1930s, and quinacridone magenta, first offered during the 1950s, together with yellow produce more highly-saturated violets and greens than do the traditional red and blue.
RYB (red, yellow, blue) is the traditional set of primary colors used for mixing pigments. It is used in art and art education, particularly in painting. It predated modern scientific color theory.
Red, yellow, and blue are the primary colors of the RYB color "wheel". The secondary colors, violet (or purple), orange, and green (VOG) make up another triad, conceptually formed by mixing equal amounts of red and blue, red and yellow, and blue and yellow, respectively.
Classification of pigment colors
The RYB primary colors became the foundation of 18th-century theories of color vision as the fundamental sensory qualities blended in the perception of all physical colors and equally in the physical mixture of pigments or dyes. These theories were enhanced by 18th-century investigations of a variety of purely psychological color effects, in particular, the contrast between "complementary" or opposing hues produced by color afterimages and in the contrasting shadows in colored light. These ideas and many personal color observations were summarized in two founding documents in color theory: the Theory of Colours (1810) by the German poet and government minister Johann Wolfgang von Goethe, and The Law of Simultaneous Color Contrast (1839) by the French industrial chemist Michel Eugène Chevreul.
In late 19th and early to mid-20th-century commercial printing, use of the traditional RYB terminology persisted even though the more versatile CMY (cyan, magenta, yellow) triad had been adopted, with the cyan sometimes referred to as "process blue" and the magenta as "process red".
CMY and CMYK color models and printing processesEdit
In color printing, the usual primary colors are cyan, magenta and yellow (CMY). Cyan is the complement of red, meaning that the cyan serves as a filter that absorbs red. The amount of cyan applied to a white sheet of paper controls how much of the red in white light will be reflected back from the paper. Ideally, the cyan is completely transparent to green and blue light and has no effect on those parts of the spectrum. Magenta is the complement of green, and yellow the complement of blue. Combinations of different amounts of the three can produce a wide range of colors with good saturation.
In inkjet color printing and typical mass productionphotomechanical printing processes, a black ink K (Key) component is included, resulting in the CMYK color model. The black ink serves to cover unwanted tints in dark areas of the printed image, which result from the imperfect transparency of commercially practical CMY inks; to improve image sharpness, which tends to be degraded by imperfect registration of the three color elements; and to reduce or eliminate consumption of the more expensive color inks where only black or gray is required.
Purely photographic color processes almost never include a K component, because in all common processes the CMY dyes used are much more perfectly transparent, there are no registration errors to camouflage, and substituting a black dye for a saturated CMY combination, a trivial prospective cost-benefit at best, is technologically impractical in non-electronic analog photography.
Wikimedia Commons has media related to Subtractive colors.
ReferencesEdit
^Levoy, Marc. "Additive versus subtractive color mixing". graphics.stanford.edu. Retrieved 4 November 2020. On the other hand, if you reflect light from a colored surface, or if you place a colored filter in front of a light, then some of the wavelengths present in the light may be partially or fully absorbed by the colored surface or filter. If we characterize the light as an SPD, and we characterize absorption by the surface or filter using a spectrum of reflectivity or transmissivity, respectively, i.e. the percentage of light reflected or transmitted at each wavelength, then the SPD of the outgoing light can be computed by multiplying the two spectra. This multiplication is (misleadingly) called subtractive mixing.
^Williamson, Samuel J; Cummins, Herman Z (1983). Light and Color in Nature and Art. New York: John Wiley & Sons, Inc. pp. 28–30. ISBN0-471-08374-7. Thus subtractive color mixing laws that successfully describe how light is altered by nonspectral filters also describes how light is altered by pigments.
Further readingEdit
Berns, Roy S. (2000). Billmeyer and Saltzman's Principles of Color Technology, 3rd edition. Wiley, New York. ISBN0-471-19459-X.
Stroebel, Leslie, John Compton, Ira Current, and Richard Zakia (2000). Basic Photographic Materials and Processes, 2nd edition. Focal Press, Boston. ISBN0-240-80405-8.{{cite book}}: CS1 maint: multiple names: authors list (link)
Wyszecki, Günther & W. S. Stiles (1982). Colour Science: Concept and Methods, Quantitative Data and Formulae. Wiley, New York. ISBN0-471-02106-7.
External linksEdit
Stanford University CS 178 interactive Flash demo comparing additive and subtractive color mixing.
August 27, 2023
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This article includes a list of general references but it lacks sufficient corresponding inline citations Please help to improve this article by introducing more precise citations January 2012 Learn how and when to remove this template message Subtractive color or subtractive color mixing predicts the spectral power distribution of light after it passes through successive layers of partially absorbing media This idealized model is the essential principle of how dyes and pigments are used in color printing and photography where the perception of color is elicited after white light passes through microscopic stacks of partially absorbing media allowing some wavelengths of light to reach the eye and not others and also in painting whether the colors are mixed or applied in successive layers Subtractive color mixingAn 1877 color photo by Louis Ducos du Hauron a French pioneer of color photography The overlapping subtractive yellow cyan and red magenta image elements can be seen clearly along the edges of the image Contents 1 Process 2 Painting 3 RYB 4 CMY and CMYK color models and printing processes 5 See also 6 References 7 Further reading 8 External linksProcess EditThe subtractive color mixing model predicts the resultant spectral power distribution of light filtered through overlaid partially absorbing materials on a reflecting or transparent surface Each layer partially absorbs some wavelengths of light from the illumination spectrum while letting others pass through resulting in a colored appearance The resultant spectral power distribution is predicted by sequentially taking the product of the spectral power distributions of the incoming light and transmissivity at each filter 1 Painting EditThe subtractive model also predicts the color resulting from a mixture of paints or similar medium such as fabric dye whether applied in layers or mixed together prior to application In the case of paint mixed before application incident light interacts with many different pigment particles at various depths inside the paint layer before emerging 2 Art supply manufactures offer colors that successfully fill the roles of the subtractive primary colors magenta and cyan For example the phthalocyanine blues which became available during the 1930s and quinacridone magenta first offered during the 1950s together with yellow produce more highly saturated violets and greens than do the traditional red and blue RYB Edit An RYB color wheelMain article RYB color model RYB red yellow blue is the traditional set of primary colors used for mixing pigments It is used in art and art education particularly in painting It predated modern scientific color theory Red yellow and blue are the primary colors of the RYB color wheel The secondary colors violet or purple orange and green VOG make up another triad conceptually formed by mixing equal amounts of red and blue red and yellow and blue and yellow respectively Classification of pigment colorsThe RYB primary colors became the foundation of 18th century theories of color vision as the fundamental sensory qualities blended in the perception of all physical colors and equally in the physical mixture of pigments or dyes These theories were enhanced by 18th century investigations of a variety of purely psychological color effects in particular the contrast between complementary or opposing hues produced by color afterimages and in the contrasting shadows in colored light These ideas and many personal color observations were summarized in two founding documents in color theory the Theory of Colours 1810 by the German poet and government minister Johann Wolfgang von Goethe and The Law of Simultaneous Color Contrast 1839 by the French industrial chemist Michel Eugene Chevreul In late 19th and early to mid 20th century commercial printing use of the traditional RYB terminology persisted even though the more versatile CMY cyan magenta yellow triad had been adopted with the cyan sometimes referred to as process blue and the magenta as process red CMY and CMYK color models and printing processes EditMain articles CMY color model and CMYK color model Cyan magenta and yellow color filtersIn color printing the usual primary colors are cyan magenta and yellow CMY Cyan is the complement of red meaning that the cyan serves as a filter that absorbs red The amount of cyan applied to a white sheet of paper controls how much of the red in white light will be reflected back from the paper Ideally the cyan is completely transparent to green and blue light and has no effect on those parts of the spectrum Magenta is the complement of green and yellow the complement of blue Combinations of different amounts of the three can produce a wide range of colors with good saturation In inkjet color printing and typical mass production photomechanical printing processes a black ink K Key component is included resulting in the CMYK color model The black ink serves to cover unwanted tints in dark areas of the printed image which result from the imperfect transparency of commercially practical CMY inks to improve image sharpness which tends to be degraded by imperfect registration of the three color elements and to reduce or eliminate consumption of the more expensive color inks where only black or gray is required Purely photographic color processes almost never include a K component because in all common processes the CMY dyes used are much more perfectly transparent there are no registration errors to camouflage and substituting a black dye for a saturated CMY combination a trivial prospective cost benefit at best is technologically impractical in non electronic analog photography See also EditAdditive color Color mixing Color motion picture film Color space Color theory Primary color Wikimedia Commons has media related to Subtractive colors References Edit Levoy Marc Additive versus subtractive color mixing graphics stanford edu Retrieved 4 November 2020 On the other hand if you reflect light from a colored surface or if you place a colored filter in front of a light then some of the wavelengths present in the light may be partially or fully absorbed by the colored surface or filter If we characterize the light as an SPD and we characterize absorption by the surface or filter using a spectrum of reflectivity or transmissivity respectively i e the percentage of light reflected or transmitted at each wavelength then the SPD of the outgoing light can be computed by multiplying the two spectra This multiplication is misleadingly called subtractive mixing Williamson Samuel J Cummins Herman Z 1983 Light and Color in Nature and Art New York John Wiley amp Sons Inc pp 28 30 ISBN 0 471 08374 7 Thus subtractive color mixing laws that successfully describe how light is altered by nonspectral filters also describes how light is altered by pigments Further reading EditBerns Roy S 2000 Billmeyer and Saltzman s Principles of Color Technology 3rd edition Wiley New York ISBN 0 471 19459 X Stroebel Leslie John Compton Ira Current and Richard Zakia 2000 Basic Photographic Materials and Processes 2nd edition Focal Press Boston ISBN 0 240 80405 8 a href Template Cite book html title Template Cite book cite book a CS1 maint multiple names authors list link Wyszecki Gunther amp W S Stiles 1982 Colour Science Concept and Methods Quantitative Data and Formulae Wiley New York ISBN 0 471 02106 7 External links EditStanford University CS 178 interactive Flash demo comparing additive and subtractive color mixing Retrieved from https en wikipedia org w index php title Subtractive color amp oldid 1169228218, wikipedia, wiki, book, books, library,
