The present invention relates to an illumination device (100) comprising a plurality of light sources (111) emitting light, an optical gate (130); a light collector (120) arranged between the light sources and optical gate and an optical projecting system (140) adapted to image the optical gate (130) at a distance along the optical axis (150). The light collector (120) is adapted to collect light from a plurality of light sources (111) and where the light collector comprises a plurality of lenslets (121) collecting light from the light sources (111) and convert the light into a plurality of light beams propagating along an optical axis (150). The lenslets (121) are arranged in a dense pattern including adjacent lenslets, where the lenslets of at least some of the pairs of the adjacent lenslets have different optical power and wherein the exit surfaces of the pairs of the adjacent lenslets having different optical power meet along a boundary.