Abstract:
The fish-eye lens system has the characteristics of plane symmetry, large field of view and large aperture imaging. That makes fish-eye lens design very complicated. Wave aberration theory is an important means to study optical system. Because the fish-eye lens system has the imaging characteristics of plane symmetry, Seidel primary aberration and higher-order aberration theory based on axisymmetric optical system are no longer suitable for aberration analysis and design of the fish-eye lens systems. The theory of sixth-order wave aberration was introduced, including the sixth-order intrinsic wave aberrations, the fifth-order aberration, transverse aberrations and the influence of the second-order accuracy of the aperture ray on the wave aberration. The flow chart of fish-eye lens system design based on sixth-order wave aberration theory was given. The former optical group of fish eye lens was designed based on sixth-order wave aberration theory, and the latter optical group design was obtained by balancing the aberrations of former group and latter group. Finally, a fish-eye lens system with good imaging quality was obtained. Its focal length is 5.989 mm, its field of view angle (FOV) is 180°, and its relative aperture is 1/3.2. The design results show that the modulation transfer function (MTF) of the fish-eye lens system is no less than 0.56 when the spatial frequency is 60 lp/mm. This fish-eye lens system has better imaging quality.