翻訳と辞書 Words near each other ・ Petyr Baelish ・ Petyt ・ Petz ・ Petz (disambiguation) ・ Petza'el ・ Petzeck ・ Petzen ・ Petzenkirchen ・ Petzite ・ Petzl ・ Petzl Croll ・ Petzl Stop ・ Petzold ・ Petzval (crater) ・ Petzval field curvature ・ Petzval lens ・ Petäjä ・ Petäjävesi ・ Petäjävesi Old Church ・ Petén ・ Petén Basin ・ Petén Department ・ Petén FC ・ Petén-Veracruz moist forests ・ Petér Bikár ・ Petín ・ Petőfi ・ Petőfi '73 ・ Petőfi Bridge ・ Petőfi Csarnok Dictionary Lists mini英和辞書 mini和英辞書 Webster 1913 Latin-English FOLDOC Wikipedia English ウィキペディア

翻訳と辞書　辞書検索 [ 開発暫定版 ] スポンサード リンク Petzval lens ： ウィキペディア英語版 Petzval lens The Petzval lens was developed in 1840 by Joseph Petzval. It consisted of two doublet lenses with an aperture stop in between. The front lens is well corrected for spherical aberrations but introduces coma. The second doublet corrects for this and the position of the stop corrects most of the astigmatism. However, this results in additional field curvature and vignetting. The total field of view is therefore restricted to about 30 degrees. An f-number of 3.7 was achievable, which was considerably faster than other lenses of the time. The speed of the lens is ideal for portrait photography since the exposure time could be reduced. In 2013 Lomography successfully launched a crowdfunding campaign at kickstarter.com to produce a new Petzval lens in Russia for film and digital cameras.〔(Kickstarter )〕 ==References== 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Petzval lens」の詳細全文を読む スポンサード リンク 翻訳と辞書 : 翻訳のためのインターネットリソース Copyright(C) kotoba.ne.jp 1997-2016. All Rights Reserved.