Five- or six-lens achromatic anamorphotic telescopes.

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.