1. An image processing array for comparing light levels from different image sources, the array comprising multiple pixel elements, each pixel element having: a first photo detector having an anode and a cathode, the first detector in exposure to a light level from a first image source; and a second photo detector having an anode, and a cathode, the second detector in exposure to a light level from a second image source, the anode of the second detector being electrically coupled to the cathode of the first photo detector, and the cathode of the second detector being electrically coupled to the anode of the first detector.