快门是照相机上用来控制胶卷有效曝光时间的核心部件。早期的感光材料感光度很低，照相机上是没有快门的。随着新的感光材料的不断发现和乳剂感光灵敏度的不断提高，为了适应摄影者对控制照相曝光过程的新要求，照相机上才出现了快门，我们现在能见到的胜界上最早的名符其实的 The shutter is a central part of the camera that controls the effective exposure time of the film. The sensitivity of early light sensitive materials is very low, the camera is no shutter. With the continuous discovery of new light-sensitive materials and the increasing sensitivity of emulsions, the shutter on the camera has emerged in response to the photographer’s new requirements for controlling the photographic exposure process, and we can now see the earliest known characters in the world In fact