Photography's system of objects changes as technology advances. It consists of traditional silver halide photography and digital photography. And in the category of traditional photography there are black-and-white or color films. The combinations of different developing skills or developers applied in the dark rooms produce all kinds of effects. And in the category of digital photography, the monitors presenting the images, network transmission, softwares, layouts, among other tools for various unusual visual works are also a part of the system. “Photograms” were created right after photography was invented. Carefully considering the principles of photography, we realize that images are produced by the substances of imaging and the source of imaging. Films and photo papers are substances of imaging, and the objects to be projected and light are the source of imaging. Photosensitive substances receive messages from the source and formulate images. These ideas have pushed the material mediums of abstract photography to the extreme.