翻訳と辞書 Words near each other ・ Stopped note ・ Stopped on Track ・ Stopped process ・ Stopped-rotor combat aircraft ・ Stoppelberg ・ Stoppeldijk ・ Stoppelsberg ・ Stoppelsberg (Sinn valley) ・ Stopper ・ Stopper knot ・ Stoppie ・ Stoppila Sunzu ・ Stopping and Range of Ions in Matter ・ Stopping at Slowyear ・ Stopping by Woods on a Snowy Evening ・ Stopping down ・ Stopping house ・ Stopping power ・ Stopping power (particle radiation) ・ Stopping sight distance ・ Stopping Tax Offenders and Prosecuting Identity Theft Act of 2013 ・ Stopping the clock ・ Stopping the Show ・ Stopping the tide ・ Stopping thought ・ Stopping time ・ Stopping Trained in America PhDs From Leaving the Economy Act ・ Stoppingas ・ Stoppit and Tidyup ・ Stoppomat 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 Stopping down ： ウィキペディア英語版 Stopping down In photography, stopping down is the act of increasing the f-stop number, thus decreasing the size (aperture) of the iris of a lens, for example, stopping down from 2 to 4. Reducing the aperture increases the depth of field of the image and allows less light to reach the film plane. To achieve the same exposure after stopping down, it is necessary to compensate for the reduced light by increasing the exposure time, using a photographic film with a higher speed, or adding more light by employing or increasing the strength of electronic flash. In digital cameras, increasing the light sensitivity of the sensor can also compensate for the reduced light In general, stopping down increases image sharpness. This is true for out-of-focus objects, and for cameras with inexpensive or simple lenses, because spherical aberration, coma and astigmatism are less apparent at smaller apertures. High-quality lenses are corrected for these aberrations, and usually give the sharpest images for in-focus objects at about one or two f-stops below maximum aperture. When using very small apertures, diffraction reduces sharpness. One generally obtains a sharper image by stopping down one or two f-stops because lens designers optimise their designs for a compromise between admitting the most light to shorten the exposure time and producing a sharply focused image. If the lens designer optimised for sharpness only, the lens would have a smaller maximum aperture which would be too dim for some poorly lit scenes. ==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「Stopping down」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.