A motion detector camera includes a camera mechanism mounted inside a housing, a motion detector exposed on a surface of the housing, and a controller for controlling the camera mechanism in response to signals received from the motion detector. The housing defines a retention portion on an upper surface of the housing. The external turbulator member includes a step positioned at the second end of the centerbody. An adjustable length conveyor belt enables the discharge of conveyed articles into the feeder at differing positions, depending upon the size of the articles. The gain correction signal modifies a signal output to a gain driver that may be AC coupled to the cathode.