照相机快门 meaning in Chinese

camera shutter

Film 16 mm ; position of film relative to camera aperture ; position of reference perforation hole
16mm电影胶片.胶片相对于照相机快门的定位.基准穿孔
The amount of light that enters the lens can be controled by the length of time the camera shutter is open for ( the exposure ) , and the width of the aperture ( the fstop )
进入镜头光的总量可以由照相机快门打开时间的长短（曝光）和孔径的宽度决定。