Description: Other Image tube based systems emerged in the 1950s which incorporated a modified GenI image intensifier with additional deflector plates which allowed a photon image to be converted to a photoelectron beam. The image, while in this photoelectron state, could be shuttered on and off as short as a few nanoseconds, and deflected to different areas of the large 70 and 90 mm diameter phosphor screens to produce sequences of up to 20+ frames. In the early 1970s these camera attained speeds up to 600 Million frame/s, with 1 ns exposure times, with up to 15 frames per event. As they were analog devices there were no digital limitations on data rates and pixel transfer rates. Images were projected and held on the tube's phosphor screen for several milliseconds, long enough to be optically, and later fiber optically, coupled to film for image capture. This technology remained state of the art until the mid 1990s when user demand dictated instant results in digital format leading to the development of the Intensified CCD type cameras.