Lessing N V
Appl Opt. 1969 Nov 1;8(11):2211-4. doi: 10.1364/AO.8.002211.
The substitution of doublets (cemented or with broken contact) for the third, fourth, or both lenses of a four-lens achromatic anamorphotic telescope is discussed. Methods for finding the glasses, the glass compounded from these, and the component powers of such a doublet are described. The two cases of the doublets having component powers of the same or opposite sign are considered. It is found that by this means the length of the lens can be reduced which makes possible the attainment of lower values of the angular magnification in the first principal section. Illustrative examples are given.
讨论了用双合透镜（胶合或有间断接触）替换四透镜消色差变形望远镜的第三、第四或两个透镜的情况。描述了寻找玻璃材料、由这些材料合成的玻璃组合以及这种双合透镜的各组分光焦度的方法。考虑了双合透镜各组分光焦度具有相同或相反符号的两种情况。发现通过这种方法可以减小透镜的长度，这使得在第一主截面中获得较低的角放大率值成为可能。给出了示例。
