Abstract: Visual inspection apparatus for the interior of conduits has a protective, cylindrical housing filled with inert gas under superatmospheric pressure. A radial end wall of the housing has a transparent central portion and at least one transparent peripheral portion. The objective lens system of a TV camera is mounted in the housing cavity behind the central portion. Electric light sources are mounted in the housing behind the peripheral end wall portions. Light of the source is prevented from reaching the camera on a path within the housing by an opaque partition in the housing cavity and by an opaque zone of the end wall separating the central and peripheral portions.