Abstract: An apparatus is disclosed for alternatively positioning a quartz or pinpoint light above a vacuum printing frame in a lithographic process. Either a quartz or a pinpoint light is required to produce fine line contacts, duplicates and reverses which are subsequently arranged in the desired orientation and transferred onto a printing plate for offset printing. The apparatus is located over a vacuum printing frame, or similar device, and has both the quartz light and pinpoint light attached to a movable housing. The housing is movable along two rails so as to accurately position either of the lights in its proper position over the printing frame. Movement of the housing is initiated by the operator and ceases when the housing contacts a limit switch.