精美英文欣赏:创造颜色

Creating Colors

There are two ways to create colors in a photograph. One method, called additive¹, starts with three basic colors and adds them together to produce some other colors. The second method, called subtractive², starts with white light (a mixture of all colors in the spectrum³) and by taking away some or all other colors leaves the one desired.

In the additive method separate colored lights are combined to produce various other colors. The three additive primary colors are green, red and blue (each proportions, about one third of the wavelengths⁴ in the total spectrum). Mixed in varying proportions, they can produce all colors. Green and red light mix to produce yellow, red and blue light mix to produce magenta⁵, green and blue mix to produce cyan. When equal parts of all three of these primary colored beams of light overlap⁶, the mixture appears white to the eye.

In the subtractive process, colors are produced when dye (as in paint or color photographic materials) absorbs some wavelengths and so passes on only part of the spectrum. The subtractive primaries are cyan (a blulish green), magenta (a purplish pink), and yellow; these are the pigments⁷ or dyes that absorb red, green and blue wavelengths, respectively, thus subtracting them from white light. These dye colors are the omplementary colors to the three additive primaries of red, green and blue. Properly combined, the subtractive primaries can absorb all colors of light, producing black. But, mixed in varying proportions they too can produce any color in the spectrum.

Whether a particular color is obtained by adding colored lights together or by subtracting some light from the total spectrum, the result looks the same to the eye. The additive process was employed for early color photography. But the subtractive method, while requiring complex chemical techniques, has turned out to be more practical and is the basis of all modern color films.

创造颜色

有两种方法可以使照片具有色彩。 一种叫加色法，通过把三种基本颜色相叠加以产生其它色彩。另一种叫减色法，通过去除白色(其实是光谱中所有颜色相混合的结果) 中的某些或其它所有色彩而把所需的色彩留下来。 在加色法中，不同颜色的光线混合以产生其它各种色彩。 加色法三原色是绿、红和蓝(其中每一种占据总光谱中三分之一的波长)。

这三种色彩以不同比例相叠加可以产生所有色彩。 绿光和红光叠加可产生黄色，红光与蓝光叠加可产生品红色，绿光与蓝光叠加可产生青绿色。 当这三种原色光以相同比例叠加时，眼睛所见的就成为白色。 而在减色法中，染料(比如在绘画颜料或彩色照相材料中)吸收了部分波长而只允许分光谱通过，从而产生各种色彩。 减色法三原色是青绿色、品红(略带紫色的粉红色)和黄色； 也就是可分别吸收红光、绿光和蓝光的色料或染料，从而去除白色光中的这些色彩。这些染料色是加色法的三原色红、绿、蓝的相互补充。 适当组合时，减色法三原色能吸收光线中的所有色彩，产生黑色。 但当它们以不同的比例叠加时，也能产生光谱中所有颜色。 不论某种颜色是通过把不同色彩的光线叠加还是把光谱中某些颜色的光去除掉而产生的，它的视觉效果是一样的。 早期彩色摄影采用加色法。 但减色法尽管需要复杂的化学技术，最终比前者更加实用，并成为现代彩色电影的基础。

1 additive   

adj.附加的；n.添加剂

参考例句：

• Colour is often an additive in foods.颜料经常是各种食物中的添加物。
• Strict safety tests are carried out on food additives.对食品添加剂进行了严格的安全检测。

2 subtractive   

adj.负的；减法的

参考例句：

• The result is a subtractive number.结果是负数。
• Complementary to the three additive light primaries,there are three subtractive primaries.与加色法三原色互为补色的颜色为减色法三原色。

3 spectrum   

n.谱，光谱，频谱；范围，幅度，系列

参考例句：

• This is a kind of atomic spectrum.这是一种原子光谱。
• We have known much of the constitution of the solar spectrum.关于太阳光谱的构成，我们已了解不少。

4 wavelengths   

n.波长( wavelength的名词复数 )；具有相同的/不同的思路；合拍；不合拍

参考例句：

• I find him difficult to talk to—we're on completely different wavelengths. 我没法和他谈话，因为我们俩完全不对路。 来自《简明英汉词典》
• Sunlight consists of different wavelengths of radiation. 阳光由几种不同波长的射线组成。 来自辞典例句

5 magenta   

n..紫红色（的染料）；adj.紫红色的

参考例句：

• In the one photo in which she appeared, Hillary Clinton wore a magenta gown.在其中一张照片中，希拉里身着一件紫红色礼服。
• For the same reason air information is printed in magenta.出于同样的原因，航空资料采用品红色印刷。

6 overlap   

v.重叠，与…交叠；n.重叠

参考例句：

• The overlap between the jacket and the trousers is not good.夹克和裤子重叠的部分不好看。
• Tiles overlap each other.屋瓦相互叠盖。

7 pigments   

n.（粉状）颜料( pigment的名词复数 )；天然色素

参考例句：

• The Romans used natural pigments on their fabrics and walls. 古罗马人在织物和墙壁上使用天然颜料。 来自辞典例句
• The original white lead pigments have oxidized and turned black. 最初的白色铅质颜料氧化后变成了黑色。 来自辞典例句