In television transmission of medical X-ray photographs and in television X-ray fluoroscopy (e.g. during surgery), where a great brightness contrast range is presented, the illustrated system obtains a blurred video signal representative of the brightness of relatively large regions of the visible light image and adjustably selects high amplitude parts of such signal to synchronously modulate the scanning electron beam of a storage type television camera tube. In this way darker image areas are transmitted with full contrast for reproduction of fine image details as particularly required in medical X-ray technology, while excessively bright areas are attenuated to a desired degree.