文章基本信息

标题：液晶減光フィルタを用いた映像撮影効果
本地全文：下载
作者：藤掛英夫 ; 佐藤弘人 ; 菊池宏等
期刊名称：映像情報メディア学会誌
印刷版ISSN：1342-6907
电子版ISSN：1881-6908
出版年度：2001
卷号：55
期号：10
页码：1322-1328
DOI：10.3169/itej.55.1322
出版社：The Institute of Image Information and Television Engineers
摘要：A variable neutral-density filter using guest-host liquid crystal devices was fabricated for color video image sensing. The liquid crystal devices contain black dichroic dyes whose absorption is controlled by voltage applied to the device. The filter keeps the spectral balance of transmitted light almost constant for three primary color wavelength regions, even when its transmittance is changed. The fabricated filter exhibited a high extinction ratio of 70 : 1 for an applied voltage of 20 V_rms, and the color temperature shift of the transmitted light was less than 200 K. We then developed an automatic light exposure system in which the variable filter is driven so that the video signal level is kept constant. By applying aperture control of a zoom lens to this automatic exposure system, we were able to achieve a new video effect where the focal depth of a captured image could be independently controlled while keeping the video level constant.
关键词：減光フィルタ;ゲストホスト液晶;映像撮像;自動露出;被写界深度