Digital camera-equipped ground telescope

摘要

An imaging element ( 3 ) is disposed behind a group of objective lenses ( 1 ), and a retractable quick-return half-mirror ( 2 ) is disposed as an optical-path splitting means in the direction of an observation optical system between the group of objective lenses and the imaging element. Plane glass ( 9 ) for correcting an change in image-formation position caused by retraction of the quick-return half-mirror is inserted into the optical path of the imaging optical system in association with the retraction of the quick-return mirror from the optical axis of the imaging optical system. The quick-return half-mirror and the plane glass are respectively held at both ends of a mirror guide lever ( 8 ) of one rigid member to effect respective retractions and insertions. The quick-return half-mirror may be provided with an inclined plane for correcting an image-formation positional deviation in the optical axis crossing direction.