As the field angles are different between direction of flight and its perpendicularity,the baffle is made non-symmetrical,so the ratio of block may below 1/3.3.

• 由于飞行方向与垂直方向视角不同；主镜上遮光筒和次镜上遮光罩的形状可以设计成非轴对称形状；并可使系统线遮栏比降为1/3.；3;