A review is made of present possibilities in the design of large refracting telescope objectives intended for visual or detector-aided studies of the planets from ground-based observatories. The great progress in the technology of optical glass achieved during the past several decades makes it worthwhile now for one to re-examine the question of whether the performance of any large refractor made in the future can be improved. On the whole the answer is affirmative but with reservations as to the importance of such an accomplishment in modern astronomy. A comprehensive discussion is given of the optical and environmental problems encountered, and several examples are given to demonstrate the degree of improvement to be expected from both semiapochromatic and fully apochromatic objectives.
James G. Baker, "Planetary Telescopes," Appl. Opt. 2, 111-129 (1963)