An illumination assembly for an interactive input system (20), comprises at least one imaging device (60) capturing image frames of a region of interest; a plurality of illumination sources (84a, 84b, 84c) associated with the imaging device and being located at different positions relative to the imaging device, the illumination sources providing illumination to the region of interest; and a controller (72) communicating with the illumination sources, the controller conditioning the illumination sources so that the illumination sources provide illumination to the region of interest in succession, the timing of image frame capture by the imaging device being coordinated with the illumination pattern of the illumination sources.