A device includes a projection and camera system to create an augmented reality environment in which images are projected onto a scene and user movement within the scene is captured. The projection and camera system have a camera to image scattered IR light from the scene and compute time of flight values used in depth mapping of objects in the room. The system also has a projector to project the images onto the scene. The projected images and scattered IR light use a common optical path through the same lens. Additionally, an illumination system used to illuminate the scene with the IR light may also use the common optical path through the same lens. In one implementation, the projection and camera system are mounted in a movable head of a table lamp.