1. A projection system having at least two projectors, each projector configured for producing a sub-image, wherein the sub-images are adapted to be projected on a screen to form a composite image and edge portions of the sub-images are configured to overlap to form an overlap region, each projector comprising: a light source for producing an input illuminance; an integrator bar positioned between the light source and at least one SLM device and operative to accept the input illuminance from the light source and output a sub image comprising multiple images of the input illuminance; an illumination relay between the integrator bar and the SLM device; an edge blending mask placed to produce a brightness ramp in the overlap region, the edge blending mask comprising an edge pattern that is (i) shaped to gradually increase obscuration of each of the multiple illuminance images in a constant manner in the overlap region and (ii) complementary in shape to the mask of the other projector to reduce variation in illuminance of field points across the overlap region; the at least one SLM device for receiving control signals and modulating light received from the light source based on the control signals to produce the sub-image; and a projection lens for projecting the sub-image.