一、问题的提出目前,在我国弹道摄影机中常用的快门有以下三种:即旋转中心式快门;旋转盘片式快门和百叶窗式快门。旋转中心式快门的光孔是从中心打开,然后向中心关闭,所以快门的正光性好,不破坏构象的几何精度,并且它可以获得很高的光效系数(η约到90％),和很短的曝光时间,一般可达到1/250—1/300秒,甚至可达到1/1000秒或更短。旋转中心式快门 First, the issue raised At present, the ballistic cameras commonly used in our country have the following three types of shutter: the rotary center shutter; rotating disc shutter and shutter shutter. The aperture of the center-of-rotation shutter is open from the center and then closed toward the center so that the shutter has good orthophotos without breaking the conformational geometric accuracy and it achieves a very high coefficient of luminous efficiency (η around 90%) and A short exposure time, usually up to 1 / 250-1 / 300 seconds, and even up to 1/1000 seconds or less. Rotary center shutter