Subtractive primaries

Fig. 10. In each image-forming layer, developer oxidi2ed by the exposed silver haUde (Dev ) reacts with the appropriate coupler to form the corresponding subtractive primary dye, yellow, cyan, or magenta. Ar represents an aryl group and the various R s are undefined organic segments.

In colour photography the film is multilayer, each layer containing the chemicals required to produce one of the three additive or subtractive primaries. In practice, it is those processes which use the subtractive YMC primaries that dominate the market. However, even in these cases the additive process is used to record the blue, green and red components of light in three layers the yellow, magenta, cyan subtractive primaries being produced in subsequent processing. ... 

One of the simplest tristimulus colorimeters is the Lovibond Tintometer. The apparatus consists essentially of a viewing tube and light reflected from a standard white surface. One half of the field is illuminated by the light reflected by, or transmitted through, the specimen under examination. The other half is illuminated directly by a beam of standard light. Into the path of the latter beam coloured glass filters of the subtractive primaries are inserted and moved by mechanical means. 

Which of the following subtractive primary colours absorbs green ... 

Primary colors, additive n. Three colored lights from which all other colors can be matched by additive mixture. The three must be selected so that no one of them can be matched by mixture of the other two. Generally, a red, a green, and a blue are used. Additive primaries are the complements of the subtractive primaries. 

Fig. 11.2 nR,G and B emitting pixels of a CRT screen, b Overlapping additive colours produce the three subtractive primaries and white , c Two overlapping subtractive primaries remove two additive primaries leaving an additive primary. When all three overlap black is produced... 

Primary Colors, Subtractive n Colors of three colorants or colored materials which, when mixed together subtractively, result in black or a very dark neutral color. Subtractive primaries are generally cyan, magenta, and yellow, the three basic colorants used in printing, for example. 

Fig. 2.10 Color circles of the subtractive primaries (a) and the additive primaries (b). M.V. Oma...

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