An illumination device comprising: a plurality of light sources emitting light along an optical axis; an optical gate arranged along the optical axis; a light collector arranged between said plurality of light sources and said optical gate, said light collector is adapted to collect light from said plurality of light sources, said light collector comprises a plurality of lenslets adapted to collect light from the light sources and is adapted to convert the collected light into a plurality of light beams, each lenslet comprises an entrance surface where said light enters the lenslet and an exit surface where the light exits the lenslet said, light beams propagate along said optical axis and through said optical gate; an optical projecting system adapted to collect at least a part of said light beams and adapted to image said optical gate at a distance along said optical axis; wherein the lenslets are arranged in a dense pattern, wherein the lenslets comprise a plurality of outermost adjacent lenslets located along an outer circular boundary, wherein each of the outermost lenslets has the same radial distance to a center of the light collector, and wherein the dense pattern has been obtained by optimizing a packaging density defined by a ratio of a sum of areas of circular cross sections of the lenslets and an area of the outer circular boundary, characterized in that each of the outermost lenslets is in contact with two of said adjacent other outermost located lenslets, and at least 37 lenslets are provided, wherein the packaging density is at least 0.81, wherein each of the outermost located lenslets contacts a lenslet located inside the outermost located lenslets. a plurality of light sources emitting light along an optical axis; an optical gate arranged along the optical axis; a light collector arranged between said plurality of light sources and said optical gate, said light collector is adapted to collect light from said plurality of light sources, said light collector comprises a plurality of lenslets adapted to collect light from the light sources and is adapted to convert the collected light into a plurality of light beams, each lenslet comprises an entrance surface where said light enters the lenslet and an exit surface where the light exits the lenslet said, light beams propagate along said optical axis and through said optical gate; an optical projecting system adapted to collect at least a part of said light beams and adapted to image said optical gate at a distance along said optical axis; wherein the lenslets are arranged in a dense pattern, wherein the lenslets comprise a plurality of outermost adjacent lenslets located along an outer circular boundary, wherein each of the outermost lenslets has the same radial distance to a center of the light collector, and wherein the dense pattern has been obtained by optimizing a packaging density defined by a ratio of a sum of areas of circular cross sections of the lenslets and an area of the outer circular boundary, characterized in that each of the outermost lenslets is in contact with two of said adjacent other outermost located lenslets, and at least 37 lenslets are provided, wherein the packaging density is at least 0.81, wherein each of the outermost located lenslets contacts a lenslet located inside the outermost located lenslets.