Long-focus optical system and lens

The invention provides a long-focus optical system, which comprises an optical filter, a first lens, a first bonding lens, a liquid lens, a second bonding lens, a second lens and a third lens which are sequentially arranged along a main optical axis from an object side to an image side, adjusting the focusing position of the telephoto optical system by controlling the driving voltage or the driving current of the liquid lens; according to the design of the invention, the long-focus optical system can enable the lens to complete quick focusing by adjusting the voltage or driving current of the liquid lens when taking images in a small visual angle range, and compared with a transmission manual focusing mode, the scheme of the invention improves the focusing efficiency and accuracy. 本发明提供了一种长焦光学系统，所述长焦光学系统包括从物侧向像侧沿主光轴依次设置的滤光片、第一透镜、第一胶合透镜、液体透镜、第二胶合透镜、第二透镜及第三透镜，通过控制所述液体透镜的驱动电压或驱动电流来调整所述长焦光学系统的对焦位置；本发明的设计使得所述长焦光学系统在小视角范围内取图时可以通过调整液体透镜的电压或者驱动电流使得镜头完成快速对焦，相比于传动的手动对焦方式，本发明的方案提高了对焦效率和准确度。