Autogated tubes gate the image intensifier within so as to control the amount of light that gets through to the microchannel plate. The gating occurs at high frequency and by varying the duty cycle to maintain a constant current draw from the microchannel plate, it is possible to operate the tube during brighter conditions, such as daylight, without damaging the tube or leading to premature failure. Auto-gating of image intensifiers is militarily valuable as it allowed extended operational hours giving enhanced vision during twilight hours while providing better support for soldiers who encounter rapidly changing lighting conditions, such as those assaulting a building.