孔径光阑可遮掉光束中偏离傍轴较多的光线，对像的清晰度、正确性、亮度和景深等有直接影响。
The aperture may curtain off the light beams that deviate paraxial , the object clarity , which has the immediate have an effect on the accuracy , brightness and the depth of field and so on .
傍轴光线