Color. Color tone, saturation, lightness.COLOUR
the Optical area of a range of electromagnetic radiations consists of three sites: invisible ultra-violet radiations with lengths of waves from 10 and approximately to 400 nanometers found generally on their chemical and physiological action; the visible light radiations with lengths of waves from 400 to 750 nanometers perceived by an eye as light; the invisible infrared radiations with lengths of waves from 740 nanometer to 1-2 mm found generally on their photo-electric or thermal action.
SPECTRAL STRUCTURE SVETA
Izlucheniye with a certain wavelength call monochromatic.
Color of visible monochromatic radiation is determined by length of its wave. At decomposition of this world in it gradually pass with a prism in a continuous range of color one into another. It is considered to be that in some borders of lengths of waves (nanometer) of radiation the next colors have:
It is yellow - green 550-575
of Blue 440-480
of Yellow 575-585
of Blue 480-510
of Orange 585-620
of Green 510-550
of Red 620-770
Eyes of the person possesses the greatest sensitivity to is yellow - to green radiation with wavelength about 555 nanometers.
Films can have the greatest sensitivity to any other sites of a range, depending on for what purposes they are made.
The PRIMARY AND COMPLEMENTARY COLOURS
the Main call those three colors by means of which any other colors can be received. Process of obtaining other colors - color synthesis - is based on addition of primary colors (additive synthesis) or. on subtraction of primary colors from white (subtractive synthesis).
Additional call colors of radiations which at mixture (addition) create the radiation of white color. Colors of additive and subtractive synthesis belong to additional:
Blue + Yellow = White;
Green + Purple = White;
Red + Blue = White;
and also couple of intermediate flowers:
Xing - blue + Is yellow - red = White.
Primary colors of subtractive synthesis can be presented as the colors which are turning out subtraction from white color three main flowers:
White - Blue = Yellow;
White - Green = Purple;
White - Red == Blue.
COLOR TONE, the SATURATION, LIGHTNESS
Color tone (a shade of color) is designated by such terms as “ yellow “ “ green “ “ blue “ etc.
the Saturation - degree or force of expression of color tone. This characteristic of color indicates amount of paint or concentration of dye. A saturation - the subjective characteristic of color therefore usually speak “ strong " color; or “ faded " color;.
There is a dual interpretation of concept of color - as sign of coloring and as the color caused by distinctions in lighting. Comparing raznookrashenny objects, speak about their color tone. In this case understand as color tone light - shadow or light-shadow ratios. So, understand graded ratios of brightness as tone reproduction - achromatic details of the image.
Lightness - the sign allowing to compare any chromatic color with one of the gray flowers called by achromatic. Achromatic colors differ only on lightness. The lightness of flowers is associated in our consciousness with amount of black and white paint in their mix. Use lightness for the characteristic of illumination of various details. Value judgment of lightness of raznookrashenny details is defined as a result of their comparison to achromatic colors of different lightness.
Besides color tona7 a saturation and lightness use also other subjective characteristics:
yellow and red colors call warm, blue and green - cold.
The Light radiations influencing approximately and causing feeling of color subdivide MONOCHROMATIC RADIATIONS AND SPECTRAL COLOURS
on prostyv and difficult. Simple (monochromatic) radiations cannot be spread out on any other colors. The range - sequence of monochromatic radiations, corresponds to each of which a certain wavelength of electromagnetic oscillation. Distinguish three zones of radiation: Xing - violet with lengths of waves from 400 to 490 nanometers; green - from 490 to 570 nanometers and red - from 580 to 720 nanometers. These zones of a range are also zones of primary spectral sensitivity of receivers of an eye and three layers of a color film.
RADIATIONS of DIFFICULT SPECTRAL STRUCTURE AND the METAMEASURED Light COLOURS
, radiated by usual sources, and also light reflected from not shining bodies always has difficult spectral structure, i.e. consists of the sum of various monochromatic radiations. Spectral structure of light - the most important characteristic of lighting. It directly influences a color rendition when shooting on color photographic materials.
The same color can be received by mixture of various radiations. Colors of radiations which, having various spectral structure, are visually perceived by identical are called metameasured.
Metameasured colors play a large role in practice of color filmings as the light sources having identical color, but various spectral structure can give noticeable changes of color ratios on a colored film. It is important to consider it when using of the mixed lighting.
Temperature at which absolutely black body radiates light of the same spectral structure as the considered light is called color temperature. She points only to spectral distribution of energy of radiation, but not to source temperature. So, light of the blue sky corresponds to color temperature about 12 500-25 000 To, i.e. it is much higher than temperature of the sun. Color temperature is expressed in kelvins (To).
The concept of color temperature is applicable only to. to the thermal (heated) light sources. The heated solid bodies give less accurate range, consisting
from several narrow strips - lines. For them the curve of distribution of energy cannot be designated by color temperature.
Natural radiations of a firmament, though are not fully temperature (i.e. proceeding from the heated bodies), nevertheless they are characterized by color temperature rather precisely. Therefore also the colored films intended for shooting at this or that lighting designate the corresponding color temperature.
The QUANTITATIVE CHARACTERISTIC of the Colour of Any Actual Radiation COLOUR
can be reproduced by mix white with a monochromatic radiation. For this purpose it is necessary to pick up only correctly the wavelength of monochromatic radiation and the relation of its power to the power of white. Sometimes use this method at measurement of color. The measured color is designated in this case the wavelength of monochromatic radiation which needs to be mixed with white for reproduction of the measured color. Wavelength of this radiation call dominating. Determine by the relation of power of the chosen monochromatic radiation to the power of its sum with white purity of color.
Spectral colors are the purest in the sense that the big saturation for this color tone cannot be received as these colors correspond to separate monochromatic radiations without their mix with white. 1