| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical system that is appropriate for a wide-angle lens of a large diameter, and especially has a high imaging performance in which the distortion is low, images are bright, and the cost can be reduced, and to provide an imaging apparatus.SOLUTION: The optical system includes, sequentially from the object side, a first lens group having a negative refractive force, a diaphragm, and a second lens group having a positive refractive force. The first lens group is disposed on the side closest to the object, and includes a cemented lens formed by joining together a negative lens and positive lens sequentially from the object side, and a positive lens disposed on the side closest to the image surface. The first lens group satisfies the following conditional expression (1) and conditional expression (2). |
