Abstract: The invention relates to a bottle inspection apparatus wherein an image of an area, such as the base, of the bottle to be inspected is projected on to an integrated circuit device comprising an array of photodiodes arranged in a plurality of rows in combination with means to interrogate each diode in turn, along each row in turn, to provide a video signal comprising a sequence of electrical signals corresponding to the light energy each diode has received, and wherein the video signal is differentiated and means are provided for gating-out unwanted signals outside the area of the bottle to be inspected whereby to generate a differentiated video output signal representative of dirt or foreign bodies in the bottle.