To meet the requirements for short focal ratio and high-resolution, based on the formula of secondary spectrum, with Petzval system as a basic objective lens structure, the dispersion characteristics of the chosen glasses materials were analyzed. A design example of an astronomical telescope lens was made with operating wavelength between 405 - 750 nm, focal length 500mm, full field-of-view angle 3. 2°and relative aperture 1:5 after the optimization of optical design software Zemax. The result of the design shows that aberation of secondary spectrum is well corrected, the MTF of every field above 0. 52 in 100 lp/mm, meets the requirements of imaging for CCD whose effective size is 23. 7 mm × 15. 6 mm. Image quality being good, it is suitable for observation or photography of deep sky objects.%为了满足用于深空天体观测或摄影的天文望远物镜的大相对口径及高分辨力的要求,基于二级光谱的理论公式,以佩兹伐物镜作为基本结构,对所选择的玻璃材料进行了色散特性的分析.通过Zemax光学设计软件的优化,给出工作波长范围在405～750nm、焦距为500mm、视场角为3.2°、相对孔径为1∶5的设计实例.设计结果表明,该系统二级光谱得到了很好的校正,在100 lp/mm处各视场传递函数均在0.52以上,满足接收器件有效尺寸为23.7 mm×15.6mm的CCD成像要求,像面成像质量良好,适合深空天体的观测.
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