On Improving the Effectiveness of Large Telescopes

A family of two-mirror correctors has been devised in a more advanced form than that obtained by Paul in 1935. These correctors can be used in combination with any paraboloidal telescope of even the largest size and will yield a greatly enlarged photographic field without the need for refracting elements of any kind. Such correctors will be of particular use in the ultraviolet, and for space-borne telescopes into the far ultraviolet, with performance limited only by diffraction over angular fields appreciably larger than available heretofore.