| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical system that has satisfactory optical performance from focusing on an infinity object to focusing on a proximity object, and to provide an imaging apparatus and a method of manufacturing an optical system. SOLUTION: The optical system includes, in order from an object side: a positive lens group G1 of positive refractive power, which is immovable when focusing takes place; and a focusing lens group G2 disposed in contact with air and having at least one concave lens face on the object side, and is configured to perform focusing from an infinity object to a proximity object by moving the focus lens group G2 along its optical axis. The object side has a variable stop S that is disposed closer to the object than the concave lens face and that changes in stop diameter with the movement of the focus lens group G2. COPYRIGHT: (C)2011,JPO&INPIT |
