Abstract: A blending tool is described for blending sub-images of a multi-channel projection system comprising a plurality of projectors. The blending device typically has a number of adjustable optical blending means which each are adapted to be mounted on a projector of said multi-channel projection system. Using a removable controlling means allows automated controlling of at least one of the adjustable optical blending means, or a blending component thereof. The removable controlling means therefore has engaging means for temporary engaging the removable controlling means to the adjustable blending means. In a preferred version, the blending tool allows remote control of the adjustable blending means such that blending can be performed from the viewing side of the projection system, even for rear-projection systems. Furthermore a method for blending and projection systems adapted for being blended using the blending tool are provided.