In an exemplary embodiment, an X-ray image intensifier television chain includes an X-ray image intensifier, a television camera, and a monitor, and a control unit has an adjustment panel for selecting radiography and fluoroscopy parameters. The control unit is connected with a signal generator whose output is connected to a mixing stage, arranged between the television camera and the monitor, so that a signal which is dependent upon the selected parameters is generated by the signal generator and is superimposed on the video signal delivered by the television camera for the purpose of fading-in a representation of the selected parameters in the television picture of the monitor.