phase detection system
Legend
7 Optical system for focus detection 8 Image sensor 30 Plane of the vicinity of the exit pupil of the optical system for photography 31 and 32 Pair of regions 70 Window 71 Visual field mask 72 Condenser lens 73 and 74 Pair of apertures 75 Aperture mask 76 and 77 Pair of reconverging lenses 80 and 81 Pair of light receiving sections