A document photography system in which the front and rear sides of serially fed continuously moving documents are imaged on an image receptor surface, such as photographic film, which is periodically advanced. An improved optical system utilizing first and second sets of fixed mirrors and fixed common reflecting surfaces provide front and rear images of the document in which the long dimensions of the document images are perpendicular to the direction of the film motion, and the front and rear images of a given document are located end-to-end transversely of the film surface. The width of incoming documents is sensed and the film motion is incremented by amounts proportional to the indicated width of the documents.