It is analyzed that the picture quality of the silver photography is generally recognized to be superior to that of other color hard copies from the standpoint of the input/output processes of the photograph. High picture quality of the silver photography compaired with printing is owing to the continuous tone which cannot be divided macroscopically. The process from exposure to development is classified into three categories and the characteristic curves computed in each case are different. However, it is shown that the high picture quality is inherent because of a small picture element such as latent image. This character is affected by the process of development and the imperfect (partial) development contributes to improvement in quality of picture. Especially color development improves its effect. Now the development process is not controlled in view of developing latent image as it is. If we can control its process, we will get atomic level information as visible picture.