Tilted-component telescopes. Part I: theory.
A simple but unorthodox application of third-order aberration theory enables one to design a simple form of highly corrected off-axis telescope. Known as the tilted component telescope, with subclasses (a) Schiefspiegler, (b) Yolo, and (c) catadioptric herschelian (CHT), is it distinguished by axially symmetric components that frequently require only spherical curvature.
Buchroeder
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