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There are two ways to create colors in a photograph. One method, called addi tive, starts with three basic colors and adds them together to produce some othe r color. The second method, called subtractive, starts with white light (a mixtu re of all colors in the spectrum) and, by taking away some or all other colors, leaves the one desired.
In the additive method, separate colored lights combine to produce various other colors. The three additive primary colors are green, red and blue (each providi ng about one?third of the wavelengths in the total spectrum). Mixed in varying proportions, they can produce all colors. Green and red light mix to produce yel low; red and blue light mix to produce magenta; green and blue mix to produce cy an. When equal parts of all three of these primary?colored beams of light overl ap, the mixture appears white to the eye.
In the subtractive process colors are produced when dye (as in paint or colo r photographic materials) absorbs some wavelengths and so passes on only part of the spectrum .The subtractive primaries are cyan (a bluish green), magenta (a p urplish pink) and yellow; these additive primaries or dyes that absorb red, gree n and blue wavelengths respectively, thus subtracting them from white light. The se dye colors are the complementary colors to the three additive primaries of re d, green, and blue. Properly combined, the subtractive primaries can absorb all colors of light, producing black. But, mixed in varying proportions, they too ca n 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.
1 What does the passage mainly discuss?
A. Recent developments in camera technology.
B. How to make white light.
C. The additive and subtractive methods of producing color.
D. The discovery of the spectrum.
2. What color filter would absorb red wavelengths?
A. Red.
B. Cyan.
C. Magenta.
D. Yellow.
3. Which of the following is NOT a pair of additive and subtractive prim ary colors?
A. Yellow and blue.
B. Magenta and green.
C. Black and white.
D. Cyan and red.
4 What explanation is given for the use of the subtractive method in mo dern color films?
A. Subtractive colors are more realistic.
B. The subtractive process is more efficient.
C. Additive chemical techniques are too complex.
D. The additive process is still being developed.
1. C) 这是一道主旨题。通过阅读该文可知，本文主要讲述两种调色的方 法，故选项C为正确答案。
2. B) 这是一道涉及subtractive process的细节题。根据第三段第二句 “The subtra ctive primaries are cyan...respectively, thus subtracting them from white light. ” 可知减色法三原色分别是青色、洋红、黄色，它们分别从白色中吸取红、绿、蓝光波。故此 题答案为B。
3. C) 根据文章内容和上题，加色法的三原色为红、绿、蓝，减色法的三 原色为青色、洋红、黄色，没有黑色与白色，因此C为正确答案。
4. B) 根据最后一段可知通过加色法和减色法所获得的特定颜色对于人的 视觉是一样的。 加色法用于早期的彩色照片的处理，而减色法却需要复杂的化学工艺，它也证明更加实用， 也是所有现代彩色胶卷的基础。由此可知相对于加色法，减色法更有效。选项A “减色法颜 色更加现实”文中没有提及，故将之排除。
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