Two-component 'anti-zoom' lens system.

Since the effective focal length of a two-component lens system (with positive focal length for each component) changes slowly compared to the change in back focal length, such a lens system may as well be considered an approximate ‘anti-zoom’ lens, with some potential applications in microscopy. This work is related to R. Siew, "What is an 'anti-zoom lens'?".由于双组分透镜系统（two-component lens system，每个组分均具有正焦距）的有效焦距（effective focal length）相较于其后焦距（back focal length）的变化更为缓慢，因此该透镜系统可被近似视为一款‘反变焦’镜头（anti-zoom lens），在显微学（microscopy）领域具备一定应用潜力。本研究与R. Siew发表的《何为‘反变焦镜头’？》一文相关。