The C8600-Series is a high sensitive image intensifier unit developed for low light level observations such as fluorescence. High quantum efficiency of 50 % (typ.) at the peek wavelength is achieved with our Hamamatsu-original GaAsP (gallium, arsenic, and phosphorous) photocathode. Since high gain and spatial resolution are realized simultaneously, low fluorescence under a microscope can be observed in real time using Hamamatsu cameras.