摘要 |
An optical system providing a new field lens corrector group for a two mirror telescope. The field group corrector has a negative net power and allows the resulting system to have a long back focus and low obscuration while covering a wide field of view. The field corrector group provides the overall system with good Petzval curvature aberration correction characteristics because the aberration of the corrector group is of opposite sign to the Petzval curvature aberration of the two mirror system. The negative field corrector group is designed to increase the f number speed of the two mirror system.
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