my TA31F 4x32 ACOG has scary light gathering ability with a 8mm exit pupil diameter (not the correct name, but typically what it is called by Rednecks like me) if you let your eye dilate... shot a night shotgun match wearing a set of early AN/PVS-2s a lot of years ago... ran into a tree, as they wouldn't focus that close... the technology has really improved..