Abstract: A composite apparatus for the direct projection and overhead or back-projection of slides comprises a box containing a source of light with a projection lens, an overhead or back-projection screen and a mirror for reflecting, towards this overhead or back-projection screen, the light beam issuing from the lens.The means ensuring the displacement of the mirror likewise provoke a displacement to take the mirror outside the box at a distance from the lens which is a function of the focal distance thereof and which is greater than that at which the mirror lies in the case of direct projection. The overhead or back-projection screen is articulated on the upper face of the box, about a horizontal, transverse pin, so as to be able to be opened into a position inclined upwardly and forwardly, to receive the light beam reflected upwardly and rearwardly by the mirror.