An optical system includes an optical bench defining a mounting surface, an objective lens mounted to the optical bench, and an image intensifier tube. The image intensifier tube includes: (i) a housing defining an interior region and a mounting surface, and (ii) a photocathode bonded to a glass faceplate defining a faceplate surface, wherein the photocathode is positioned within the interior region of the housing, and wherein the mounting surface of the housing resides on the same plane as the faceplate surface. The mounting surface of the optical bench is mounted onto the mounting surface of the image intensifier tube housing such that the mounting surface of the optical bench resides on the same plane as the faceplate surface and the faceplate surface of the faceplate is the surface of the faceplate that is positioned closest to the objective lens.