Disclosed is an intermediate adapter to be used between the camera body and the photographing lens during close-up photography. A light beam splitter in the adapter housing projects part of the light from the lens to a sensor to produce an electric signal. An illumination device that lights a subject to be photographed is controlled by the signal produced by the light split by the light beam splitter. The beam splitter includes a diffraction arrangement that directs a portion of the light from the path to the film.