There are two ways to create colors in a photograph. One method, called additive, starts with three basic colors and adds them together to produce some other colors. The second method, called subtractive, starts with white light 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 . Mixed in varying proportions, they can produce all colors. Green and red light mix to produce yellow, red and blue light mix to produce magenta, green and blue mix to produce cyan. When equal parts of all three of these primary colored beams of light overlap, the mixture appears white to the eye. In the subtractive process, colors are produced when dye absorbs some wavelengths and so passes on only part of the spectrum. The subtractive primaries are cyan , magenta , and yellow; these are the pigments or dyes that absorb red, green and blue wavelengths, respectively, thus subtracting them from white light. These dye colors are the complementary 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.
上一篇: 12月英语四六级考试精选作文十
下一篇: 12月英语四六级考试精选作文十三
特朗普总统访问受飓风重创的北卡罗来纳州
国际英语资讯:California prohibits full-service restaurants from automatically providing plastic straws
国内英语资讯:2018 FOCAC Beijing Summit: What to expect
体坛英语资讯:Richarlison handed Brazil No. 9 shirt
国际英语资讯:Iran continues nuclear cooperation with Russia: nuke spokesman
体坛英语资讯:Brunei to face Timor-Leste in final leg of AFF Championship qualification
研究表明 多吃油性鱼类可助降低24%老年疾病
《神奇女侠2》推迟上映,据说是想寻求高票房?
国内英语资讯:China, CEE countries set cornerstone for environmental protection cooperation
To Be the Best One 做最好的自己
国际英语资讯:Woman kills herself after shooting dead 3 in U.S. Maryland
Childhood 童年
情感专家告诉你:如何“科学地”说分手
国内英语资讯:China rolls out further tax cuts in support of real economy
体坛英语资讯:Kenya team to have good performance at Youth Olympic Games despite missing out in swimming
国际英语资讯:South Sudanese president arrives in Khartoum for official visit
体坛英语资讯:Top players set to battle it out in 2018 Wuhan Open qualifying rounds
国内英语资讯:Premier Li vows to brave challenges, bolster economy
国际英语资讯:Spotlight: EUs Tusk says Mays Chequers plan wont work
国内英语资讯:Top political advisor stresses full implementation of major policies in Ningxia
国际英语资讯:S. African president unveils economic stimulus plan
国际英语资讯:U.S. says DPRKs denuclearization has to come first
国际英语资讯:U.S. state announces accord with federal govt on nuclear waste site
敢不敢乘坐泰坦尼克2号?这次可是带够了救生艇和救生衣
体坛英语资讯:Wang Qiang, top-10 players into semis of China Open
睡不着?也许是因为你太累了
为王室身份而放弃社交媒体,梅根坦言很轻松!
国内英语资讯:Senior lawmakers hear reports on draft laws, resolutions
体坛英语资讯:German national team coach praises French football ahead of Nations League clash
国内英语资讯:Xi stresses building pilot FTZs toward new heights of reform, opening-up