| 摘要 |
PROBLEM TO BE SOLVED: To provide a zoom lens which is capable of performing focusing at high speed coping with moving image photography, regardless of a compact zoom lens and has high image formation performance and to provide an imaging apparatus.SOLUTION: The zoom lens comprises, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a fourth lens group having negative refractive power. The fourth lens group comprises only one negative lens or a cemented lens obtained by cementing a positive lens and a negative lens in order from the object side. When performing focusing, the fourth lens group is moved in an optical axis direction. The zoom lens satisfies the following conditional expression: 0.7<(R4f+R4r)/(R4f-R4r)<5 (1), where R4f is the curvature radius of the surface on the most object side of the fourth lens group, and R4r is the curvature radius of the surface on the most image side of the fourth lens group. |
