| 摘要 |
A-FOV (field ofobjectivecomprises immovable first and fourth positive components and two movable components arranged between movable components and having two fixed positions at optical axis to change viewing fields. First movable positive component is made as meniscus with convexity oriented towards the image plane, second movable component comprises two negative meniscus with convexities oriented towards each other and a positive lens. The last component comprises a positive meniscus and negative one with convexities oriented towards the image plane, and a positive meniscus and negative one with concavities oriented towards the image plane. In the first component the negative meniscus is displaced to first place, second movable component is removed, in the third movable component the positive lens is removed, in the last component third meniscus is positive one, and fourth component is negative one. |
