They respond to the total amount of light falling on them over the period of time during which they are exposed .
它们感应的是在一段曝光时间内落在它上面的光的总量。
织梦好，好织梦
For the study of impact problems, very short exposure times and high picture repetition rates are required .
为了研究冲击问题，需要很短的曝光时间和较高的画幅移动速率。 内容来自dedecms
One will choose an exposure time which is a good compromise between the times required for the blue and the red rays .
可以选择一个介于红光和蓝光所需要的曝光时间之间的折衷值作为曝光时间。 copyright dedecms