An X-ray emitter, particularly a dental X-ray apparatus, includes an X-ray source disposed in a housing, wherein the interior housing has an emission aperture and a diaphragm is provided which delimits the X-rays leaving the emission aperture to form a X-ray fan beam and is disposed at a distance from said emission aperture. In the space between the emission aperture and the diaphragm there are disposed radio-transparent means for deflecting light waves in the visible range, and in or on said housing there is provided an image detection system for the deflected light waves.