Abstract: Apparatus including a stepping camera, partitioning means and an operating station is disclosed in which full size images of copy successively mounted on a subject holder can be optically imposed on preselected areas of a film (or a printing plate) in a required sequence when supported on a movable platen under control of a digitally programmed indexer. The camera components including the subject holder, objective support, image mask, platen and supporting structure therefor are so structured and related as to assure accurate placement of the images on a film in a programmed sequence at high speed and in such fashion that the images are uniformly sharp and of high resolution. The camera includes interchangeable subject holders such that it is equally useful with reflection copy, transparent originals and negative or positive film.