The single camera modules, 1 to an maximum of 8, are autonomous units and are mounted inside the optics frame.The font end electronics, with signal conditioning, analog digital conversion, CCD timing and processing is directly integrated inside the camera modules. In this way best S/N (Signal to Noise) of the CCD-signals is ensured and EMI (Electro Magnetic Interference) within the system is minimized. The electromechanical shutter is placed in the center of the lens. The advantage of this solution is an distortion free image, since all image points are exposed through the same optical path at the same moment in time. A slit shutter, as used in a standard reflex camera, causes geometric distortion inside the image field, since the aircraft is moving during exposure time. The shutter is driven by wear resistant piezoelectric actuators, thus enabling a minimum of moving parts to ensure very high reliability. This special design, combined with a sophisticated electronic control loop, incorporates shutter and iris function in one compact optoelectronic unit. A focus of the shutter development was to achieve precise synchronization of all lenses to ensure exposure of all images at exactly the same time interval in order to exclude geometric errors.