القيم السالبة في تركيب الألوان .. كتاب التصوير الملون ، الكاتب عبد الفتاح رياض

Negative values ​​in the composition of colors: As we have seen from the above, the triangle (HQ) does not include the origins of all the highly saturated Hue colors, which result from mixing or two primary, so we find in (Fig. 25) the previous triangle HQ after its expansion to indicate the location of those colors. Indicate the wavelengths of light that indicate the origin of color. It is seen in this figure that point (h) represents all light wavelengths up to 7600 angstroms, as no difference is seen in the spectrum between the colors of those light waves whose lengths lie between (7000-7600 angstroms). We also see in the figure a new point (b) indicating the location of the violet color (with a light wavelength of 3900 angstroms), which is located after the blue color in the order of the spectrum colors. We have mentioned before that it is possible to form colors from mixing the three primary colors (red - green - blue) in different proportions, and in this case the color must be present within the triangle Z H S (Fig. 24). But it may seem at first glance that there is a contradiction between what we have mentioned and what we see in (Fig. 5100 angstroms does not consist of these three primary colors, but rather consists of two colors, namely blue (S) and green (Z). Therefore, we explain this contradiction in (Fig. (25).-

(Fig. 25) Negative values ​​in the composition of colors

(1) That is, 0100 + hk = s .. And since the color from can also be composed by sewing an amount of blue (q), and let it be symbolized by (q) with another amount of green (n), and let us symbolize it (mk).

(2) ... s = ( s k ) + ( n k ) . . ... We conclude from equations No. 1 and 2 that the color is 5100 + hk = = zk + kk. - h k + z k + s k ().

It appears in the figure above that it mixes an amount of color whose light wavelength = 5100 angstroms with an amount of color around its symbol (h (k). We will have a medium color that is (x).

Equation No. 4 above shows us that it is mathematically possible to obtain a color whose light wavelength is 5100 anstrom from adding an appropriate amount of blue to another amount of green and an appropriate amount of red, and therefore it is considered a negative quantity. color with discount

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Dr. P. J. Bouma Physical aspects of colour. P. 56.