A cathode ray tube mounting means includes a front panel member having an opening through which a cathode ray tube is passed, and it has projections on its funnel section that mate with wedging members movably mounted in the panel member. A bezel having an implosion shield means therein is secured onto the front panel member and the wedging members are secured into position thereby moving the faceplate of the cathode ray tube into tight engagement with the implosion shield means. Lighting means is disposed between the front panel member and the bezel adjacent the faceplate to effectively light the graticule scale of the cathode ray tube screen and to permit easy replacement of light bulbs. A connecting means is also provided for electrically connecting a camera to the circuitry within the electronic instrument containing the cathode ray tube.