| 摘要 |
The present invention provides in one embodiment a Newtonian type reflecting telescope, preferably using a primary parabolic reflecting mirror, in which a meniscus lens is used to simultaneously correct for coma aberrations of both the primary reflector and of an eyepiece lens used for viewing the image, as well as for spherical aberration of the eyepiece. In some embodiments, the meniscus correcting lens is moveably mounted so that in one position it is used in connection with a viewing eyepiece, correcting the above-mentioned aberrations of primary reflector and eyepiece; while in a second position this same correcting lens is used with a lensless camera mounted on the telescope, in this case properly correcting the system only for the coma of the primary reflector. In all cases, the field of view, and magnification, of the telescope remains unchanged or only negligibly changed. In some additional embodiments, power is added to the meniscus lens to provide a new type of powered corrector. With this new corrector, a rather ordinary telescope, i.e., with an optically slow primary mirror as its objective, can be used in a dual mode, with bright, well corrected, wide field imagery at lower magnification with the corrector in the optical path, and in the ordinary higher power mode when the corrector is removed from the optical path.
|
