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Proceedings Paper

Utilization Of Moving Lens Elements For Compensation Of Aberrations Resulting From Major Conjugate Changes
Author(s): Ellis I. Betensky
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Paper Abstract

There are many lenses, particularly those used in photographic applications, which are focused for different object positions, forming images at different magnifications. Moving the entire lens assembly along the lens axis while the object or image locations are unchanged is termed a conjugate shift, and because the lens aberration correction is well maintained for a small conjugate shift for most lenses, this has become the traditional focusing technique. Newly designed, compact telephoto and wide angle lenses, however, do not have a stability of correction over a sufficiently large range of conjugate distances to satisfy the needs of the photographer, and thus employ various mechanical techniques to compensate for the aberration change. In addition to these "extreme" lenses, the question of how much normal lenses degrade in performance over a large conjugate change, say m'.0 to m'.-.3 arises, followed by the question of whether normal lenses can be designed which will be uniformly corrected over such large ranges. This paper discusses the limitations of some popular lens types, and shows some methods which can be employed to achieve the desired uniformity.

Paper Details

Date Published: 1 March 1974
PDF: 8 pages
Proc. SPIE 0039, Applications of Geometrical Optics II, (1 March 1974); doi: 10.1117/12.953788
Show Author Affiliations
Ellis I. Betensky, Opcon Associates, Inc. (United States)

Published in SPIE Proceedings Vol. 0039:
Applications of Geometrical Optics II
Warren J. Smith, Editor(s)

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