Abstract: The slide projector (4) for single-slide, lap-dissolve or stereo projection, which works on the gravity feed principle, is designed for operation with linear slide trays (1, 2) divided into compartments. At the top, it has either two receptacles for slide-tray covers (2, 5) or one receptacle (4g) and one cover (4h) integral with the housing of the projector. When being placed on the projector, the slide tray is automatically unlocked, so that the housing of the tray becomes shiftable. Switching means ensure that the projector cannot operate until the slide tray is properly positioned. The projector also has a variable electronic light intensity control facility. It initiates no projection when a tray compartment is empty.The slide tray (1, 2) is so designed that slides are loaded into the housing (1) of the tray from above in an upright and laterally correct image position; the housing (1) is then closed with the cover (2). During projection, the cover forms the bottom of the slide tray.