An illumination system, used for illuminating a target area, includes a plurality of light generating elements and a plurality of light collection units disposed to collect light from respective light generating elements. Imaging lens units are disposed to relay images of respective light collection units to the target area, light from different light generating elements overlapping at the target area. In some embodiments, the illumination system also includes color combining elements to combine light from differently colored light generating elements. The illumination system may be used in a projection system, with the light from the illumination system incident on an image-forming device placed at the target area.