The Acme telescope is a compound telescope that resembles the familiar Cassegrain type except that the main mirror is spherical and the secondary is an achromatic doublet mangin mirror. Three 6-in, aperture f/15 telescope designs are described. With a cemented, all spherical surface achromangin mirror, there is a small amount of coma which can be eliminated by redesigning with an air space between the crown and flint elements of the achromangin mirror, or by cementing them with one of the concave external surfaces of achromangin figured to an hyperboloid. In the examples, the spherical aberration is nil and the chromatic residual is roughly half that of an achromatic objective of the same speed, aperture, and glass types. Readily available crown and flint glasses such as Schott BK-7 and F-2 are entirely satisfactory for the achromangin mirror. Also considered are two examples of Acme-like telescopes with paraboloidal instead of spherical main mirrors.

Date Published: 30 December 1981
PDF: 5 pages
Proc. SPIE 0288, Los Alamos Conf on Optics '81, (30 December 1981); doi: 10.1117/12.932020

Published in SPIE Proceedings Vol. 0288:
Los Alamos Conf on Optics '81
Donald H. Liebenberg, Editor(s)