A night-vision camera is a video/audio recording device that uses night-vision to see in dimly lit areas. Despite popular belief, it is impossible to effectively use NV (night-vision) if there is no light source and these devices typically emit their own minute light barely enough to see a full room.
Night-vision works by greatly amplifying any and all sources of light caught in the camera's scope, and can make a small match work well enough to see a full room, but its use can only be fully effective when seen through the screen. Anyone in the presence of a user of NV can not see the same amount of light the NV user sees. NV cameras are used commonly in paranormal investigations so as to amplify any sort of light or orb anomalies captured on film. They can be placed in stationary positions or carried alongside an investigator by a handle underhand or atop the shoulder.
It is highly recommended to never carry the cameras underhand, as any evidence captured could be questionable due to the accuracy of the camera-person being difficult to position.