dark field的用法和樣例：
例句
- For astrometric purposes, dark frame and flat field calibration is recommended.
出於天文測量要求，暗場圖和平場圖校準是被推薦的。 - The annular lens dark field vertical illumination system has been more and more applied in special microscopes.
環形透鏡暗場落射照明系統越來越多被應用在特型顯微鏡上。 - The spirals are not readily seen unless immunofluorescent stain or dark field illumination is employed.
螺旋體不易觀察除非在熒光顯微鏡或暗視野顯微鏡觀察。
