| 摘要 |
PROBLEM TO BE SOLVED: To provide an optical system suppressing the effect of changes in coating characteristics caused by coating irregularity of IRC coating of a lens surface having a curvature, and an imaging system.SOLUTION: An optical system constituting a fisheye lens whose entire view angle is 180 degree or more comprises, in order from an object side: a first lens group having a negative focal length; a diaphragm; and a second lens group having a positive focal length. An infrared cut coating is applied to a lens surface of a lens, having a curvature, of lenses included in the second lens group.SELECTED DRAWING: Figure 1 |
