翻訳と辞書 Words near each other ・ Extension method ・ Extension neglect ・ Extension neural network ・ Extension of a Man ・ Extension of a polyhedron ・ Extension of a topological group ・ Extension of the Wish ・ Extension of University Education Act, 1959 ・ Extension Poly(A) Test ・ Extension Reef ・ Extension Scouting ・ Extension Service ・ Extension studies ・ Extension topology ・ Extension transference ・ Extension tube ・ Extension, British Columbia ・ Extension, Louisiana ・ Extensional context ・ Extensional definition ・ Extensional fault ・ Extensional tectonics ・ Extensional viscosity ・ Extensionalism ・ Extensionality ・ Extensionism ・ Extensions (Ahmad Jamal album) ・ Extensions (Dave Holland album) ・ Extensions (McCoy Tyner album) ・ Extensions (The Manhattan Transfer album) 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 Extension tube ： ウィキペディア英語版 Extension tube An extension tube - also called extension ring - is used with interchangeable lenses to focus closer, useful in macro photography.〔(MACRO EXTENSION TUBES & CLOSE-UP LENSES )〕 ==Construction== The tube contains no optical elements; its sole purpose is to move the lens farther from the image plane. The farther away the lens is, the closer the focus, the greater the magnification, and also the greater the loss of light (requiring a longer exposure time). Lenses classically focus closer than infinity by moving all optical elements farther from the film or sensor; an extension tube simply enables this movement. Extension tubes without electrical contacts will not allow an electronic automatic camera to control the lens, thus disabling autofocus and in some cases forcing a user to shoot wide open unless the lens offers manual aperture control. More expensive extension tubes contain electrical contacts allowing the user to use autofocus and electronically control the aperture of the attached lens. An advantage to the non-electrical tubes is their lower price. Other items like lens adapters may unintentionally have an effect similar to an extension tube. A lens designed for a small flange focal distance may not be able to focus to infinity when a lens adapter places the sensor too far away. 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「Extension tube」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.