A research group has been focussed on iris detector imaging systems. They currently have an iris collection system that works at an object distance of 30 cm. With an unknown focal length lens, they are able to capture a zoomed in image of an iris (1 cm in diameter) which is 200 pixels wide in the final image. Their current image sensor is 640x480 resolution (old technology). The pixel size is 20 microns. They want to know if they can swap the lens and perform face recognition. Their same 640x480 image would have to cover a human face: at least 25 cm tall. What focal length would achieve this? If they wanted to do simultaneous iris and face capture they would have to also change the detector array. Assume pixel sizes today are 8 microns, what size (NxM) array would be needed to perform both tasks at once?