Vertical fc is provided by the room...not the cam. However we do have a low min lux spec as well as builtin dynamic range control and noise suppresion.  The end result is a good image in low and mixed light.  The old VTC spec for lighting was shoot for 55 fc with a 3:2 contrast with subject background.  The PTZOptics is far more forgiving than that. But to firsy question...there is no spec for min vert fc. We have a .5 lux lighting requirement to give us enough to produce a 1920x1080p image on our CMOS sensor.