Abstract

A telescope objective of 10-cm focal length may be produced with practically zero spherical aberration for all wave-lengths of the visible spectrum and for apertures up to f:2 by combining four thin lenses of crown glass (n = 1.523) of the same converging power. The lens surface curvatures approximate those of minimum aberration lenses but are in integral half diopters as follows: 1st lens, 2.5 and 0 diop.; 2nd, 4 and −1.5 diop.; 3rd, 6 and −3.5 diop.; and 4th, 7.5 and −5.0 diop. Detailed results are given for the linear spherical aberration Δf/h₁², where h₁ is the radius of the zone where the rays enter the first lens, as a function of h₁², as a function of index of refraction n, and as a function of the spacing of the fourth lens from the third. This spacing permits final adjustment to secure the least possible aberration. Minimum aberration lenses are shown to be more effective in securing zero aberration than aplanatic lenses suggested by Dunoyer.

© 1947 Optical Society of America

Recent and Unusual German Lens Designs

Edward K. Kaprelian
J. Opt. Soc. Am. 37(6) 466-471 (1947)

Focal Plane Diffraction Anomalies in Telescopic Systems*

A. I. Mahan
J. Opt. Soc. Am. 37(10) 852-867 (1947)

The Reflection of Light from Glass with Double and Multiple Films

Antonin Vašiček
J. Opt. Soc. Am. 37(8) 623-634 (1947)

Theory of Condensing Lenses for Raman Tubes of Small Volume*

J. Rud Nielsen
J. Opt. Soc. Am. 37(6) 494-499 (1947)

Apparatus for Determining Spherical Aberration of Convex Surface of Paraboloid of Revolution

Benjamin Goldberg and Nels C. Benson
J. Opt. Soc. Am. 37(3) 186-191 (1947)