When the focal length of a photographic lens is less than a first focal length, a dimming correction amount deltaY is set to a certain minus value. At least two blades are mounted on the ferrule, the blades being coupled to the ferrule in their center portions by notches that mate with the locking portion of the ferrule. Further, the edge along optical axis of the light source is set to be parallel with or inclined from the edge on the opposed-to-medium surface side of the element-integration surface. First, the dam prevents damage to the mold.