Zooming optical system

PROBLEM TO BE SOLVED: To provide a zoom optical system capable of providing high optical performance for an imaging view angle of 100 degrees or greater, as well as for an imaging view angle less than 100 degrees, at a short focal length end.SOLUTION: A zoom optical system consists of a negative first lens group, positive second lens group, negative third lens group, and positive fourth lens group, and is configured such that each lens group moves along an optical axis when zooming, the first lens group comprising at least a positive cemented lens. The zoom optical system satisfies the following conditional expression (1): -10.0