For photography process the data than the other subjects is relatively small, but as a technology, procedural makes it relatively good grasp, for the whole history of photography, including the development of photographic equipment, the evolution of the sensitive material, the development of the portrait photography, the development of the genre of photography, the emergence of you, there are some photography big and complex. So my topic is taken shadow process as the main line, the history of ancient time drive sensitive material base as the auxiliary pole. Tomography will involve the camera, from its birth to now runs into five categories: box camera, camera bellows type, reflective type camera, step imaging cameras, small camera, the silver halide film cameras (digital camera). Background collage images are mostly remembered event. The below is a timeline, record some important inventions to promote the development of photography.