陳蕙雅思教材 - 雅思閱讀精選 (Creating Colors)

Creating Colors

There are two ways tocreate colors in a photograph. One method, called

additive, starts withthree  basic colors  and adds them together to produce

some other colors.  The second method, called subtractive, startswith

white light (a mixture ofall colors in the spectrum) and by taking away

some or all other colorsleaves the one desired.

In the additive methodseparate colored lights are combined to produce

various other colors. Thethree additive   primary colors are green,red and

blue (each proportions,about one third of the wavelengths in the total    

spectrum). Mixed invarying proportions,  they can produceall colors.

Green and red light mixto produce yellow,       red and bluelight mix to

produce magenta,green  and blue  mix to produce cyan.  When equal parts

of all three  of        theseprimary colored beams of light overlap, the mixture

appears white to the eye.

In the subtractiveprocess, colors are produced when dye (as in paint or

color photographicmaterials) absorbs some wavelengths and so passes on

only part of thespectrum. The subtractive primaries are  cyan  (a  

blulish  green),      magenta  (a purplish  pink),  and yellow;  these  are  

the pigments or  dyes that absorb red, green and  bluewavelengths,    

respectively,  thus subtracting them from white light.  These dye colors

are the  complementary colors to the  three    additiveprimaries of red,  

green and blue. Properlycombined,  the subtractive primaries canabsorb  

all colors of   light, producing black. But,  mixedin  varying proportions

they too  can produce any color in the spectrum.

Whether a particularcolor  is obtained  by adding colored lights  together

or  by subtracting some light from the   total spectrum, the result looks the

same to the eye. Theadditive process was employed for early color

photography. But thesubtractive method, while requiring complex chemical

techniques,  has turned out to be  more          practicaland is the basis of all  

modern color films.

創造顏色有兩種方法可以使照片具有色彩。  一種叫加色法，通過把三種基本顏色相疊 加以產生其它色彩。

另一種叫減色法，通過去除白色(其實是光譜中所有顏色相混合的結果) 中的某些或其它所有色彩而把所需的色彩留下來。  在加色法中，不同顏色的光線混合以產

生其它各種色彩。  加色法三原色是綠、紅和藍(其中每一種佔據總光譜中三分之一的波長)。 這三種色彩以不同比例相疊加可以產生所有色彩。  

綠光和紅光疊加可產生黃色，紅光與藍 光疊加可產生品紅色，綠光與藍光疊加可產生青綠色。 當這三種原色光以相同比例疊加時， 眼睛所見的就成為白色。  

而在減色法中，染料(比如在繪畫顏料或彩色照相材料中)吸收了 部分波長而只允許分光譜通過，從而產生各種色彩。  減色法三原色是青綠色、品紅(略帶紫

色的粉紅色)和黃色；  也就是可分別吸收紅光、綠光和藍光的色料或染料，從而去除白色光 中的這些色彩。這些染料色是加色法的三原色紅、綠、藍的相互補充。  

適當組合時，減色 法三原色能吸收光線中的所有色彩，產生黑色。  但當它們以不同的比例疊加時，也能產生 光譜中所有顏色。  

不論某種顏色是通過把不同色彩的光線疊加還是把光譜中某些顏色的光 去除掉而產生的，它的視覺效果是一樣的。 早期彩色攝影採用加色法。 但減色法儘管需要

複雜的化學技術，最終比前者更加實用，並成為現代彩色電影的基礎。