| 摘要 |
PROBLEM TO BE SOLVED: To provide a high-performance variable power optical system which has a lightweight focusing lens group and compact size as an entire optical system, and yet has a vibration-proof function, and to provide an imaging optical device and digital equipment having the same.SOLUTION: A zoom lens ZL comprises, in order from an object side, a positive first group Gr1, a negative second group Gr2, a positive third group Gr3, a positive fourth group Gr4, and a negative fifth group Gr5. Focusing is performed by moving the fourth group Gr4 on an optical axis AX, and vibration-proofing is performed by moving a sub-group GrV including a lens on the most image side in the second group Gr2, in a plane substantially perpendicular to the optical axis AX. The zoom lens ZL satisfies a conditional expression: M/N<0.5 (M represents the number of lenses constituting the sub-group GrV and N represents the number of lenses constituting the second group Gr2, where a cemented lens is counted as multiple lenses.). |
