| 摘要 |
A reflecting telescope optical system comprises, a main reflecting mirror, a sub reflecting mirror which is disposed at a position facing a reflecting surface of the main reflecting mirror, and a plurality of lens units which is disposed at a position facing a reflecting surface of the sub reflecting mirror. The reflecting surface of the main reflecting mirror is a concave surface, and a reflecting area is formed to be ring-shaped. The reflecting surface of the main reflecting mirror and the reflecting surface of the sub reflecting mirror are mutually facing. The first operation is a movement for focusing at an object positioned between infinity and a near position, and the second operation is a reciprocating movement for changing the focused state after focusing. An amount of movement in the first operation is larger than an amount of movement in the second operation. |
