首页
登录
职称英语
What Is the base of film today? [originaltext] The camera is often thought
What Is the base of film today? [originaltext] The camera is often thought
游客
2023-11-08
31
管理
问题
What Is the base of film today?
The camera is often thought to be a modern invention. But as early as 1727, a German physicist discovered that light darkened silver salt, a chemical compound. Using a big box with a small hole to let the light in, he made temporary images on the salt. Silver salt is still the base of film today. Then a French scientist made the first permanent picture by using a special piece of metal sensitized with silver salt. A photograph he made in 1826 still exists. The painter Dagera improved the process by placing common salt, the kind we eat, on the metal. This was in 1839, the official date of the beginning of photography. But the problem was the printing of the photographs. And it wasn’t until other scientists developed the kind of paper we now use that good printing was possible and photography became truly modern. In 1860’s, Matthew Brady was able to take his famous pictures of the American Civil War, thus making portrait poses very popular. In the 20th century, George Eastman of the United States simplified film developing, and Edwards Land invented the so-called instant camera with self-developing film. If we say that the photography came into existence in 1839, it follows that it has taken more than one hundred years for the camera to reach its present condition of technical refinement.
选项
A、Salt.
B、Silver Salt.
C、Metal.
D、Plastic.
答案
B
解析
转载请注明原文地址:https://tihaiku.com/zcyy/3170483.html
相关试题推荐
HowmanyIsraelifootballfansareseriouslyinjured?[br][originaltext]A
HowmanyIsraelifootballfansareseriouslyinjured?[originaltext]Atleas
Whatisthedeficitforfiscal2006?[br][originaltext]TheWhiteHouseon
Whatisthedeficitforfiscal2006?[originaltext]TheWhiteHouseonWedne
WhatisMissBarnes’job?[br][originaltext]M:MissBarnes,Iunderstandthat
WhatisMissBarnes’job?[br][originaltext]M:MissBarnes,Iunderstandthat
Whatarethetwospeakerstalkingabout?[originaltext]W:Howarethingsgoingw
What’sthepurposeofthefair?[br][originaltext]M:Areyougoingtothefair
WhichdescriptionisNOTcorrectaboutthestorm?[br][originaltext]USwe
Thenumberofescapedprisonersis______.[br][originaltext]Prisonservi
随机试题
Aman’sshoppingcanbeandofteniscompletedinfiveminutes,whichisonlyle
THEFIVE—SEVENSHIFT1Allmajortheoriesofchildpsycholog
CanTeachingGrammarReallyBeFun?【T1】______amongaverageteachers-Teaching
A.宫颈锥切术 B.全子宫切除术 C.扩大子宫切除术 D.广泛性全子宫切除
Dugas征阳性A.肩关节脱位 B.肘关节脱位 C.髋关节后上脱位 D
关于氯解磷定用于中重度有机磷酸酯类中毒的解救,错误的是()A.是胆碱酯酶复
下列腧穴中,哪穴不属于本经的母穴()A.列缺 B.中冲 C.复溜 D
(1)人体肝细胞可产生一种分泌蛋白(称为蛋白A),运出细胞后进入血液。已知内质网
轻度缺氧时,血气分析PaO指标为A.86~95mmHg B.70~85mmHg
大额可转让定期存单不具备()特性。A.能转让流通 B.金额较大 C.不
最新回复
(
0
)