序言摄影过程是用相机把光学信号记录在感光材料上的过程。将已知照度分布的光学影像记录在乳剂层上,显影后,所得到的密度分布往往与照度分布不对应。密度与照度的正比关系,只有在感光材料无粒度,也没有来自片基界面的反射,亦不存在漫射时才成立。在实际摄影过程中,光学密度与给定照度不符,但与成像的有效照度相对应。 Preamble Photographic process is the use of the camera to optical signals recorded in the photosensitive material on the process. Optical images of known illuminance distributions are recorded on the emulsion layer. After development, the resultant density distribution often does not correspond to the illuminance distribution. The direct relationship between density and illuminance, only in the photosensitive material without grain, nor from the film-based interface reflection, there is no diffuse when the establishment. In actual photography, the optical density does not match the given illumination, but corresponds to the effective illumination of the image.