In an apparatus for exposing a set of discrete locations on a photosensitive surface, such as an electrophotographic printer, a scanner transmits a light beam along a scan path onto the photosensitive surface. An optical element, interposed in the scan path between the photosensitive surface and the scanner, defines a plurality of apertures therein where no more than one aperture is disposed at any location along a linear dimension of the optical element parallel to the scan direction. The light beam transmitted through each aperture exposes a discrete location on the photosensitive surface.