VARIABLE POWER OPTICAL SYSTEM, OPTICAL EQUIPMENT EQUIPPED WITH VARIABLE POWER OPTICAL SYSTEM AND VARIABLE POWER METHOD FOR VARIABLE POWER OPTICAL SYSTEM

摘要

PROBLEM TO BE SOLVED: To provide a variable power optical system having a vibration-proof function, which achieves excellent optical performance even when a camera shake is corrected, optical equipment equipped with the variable power optical system and a variable power method for the variable power optical system.;SOLUTION: The variable power optical system ZL mounted on an electronic still camera 1 or the like includes, in order from an object side, a first lens group G1 having positive refractive power, a second lens group G2 having negative refractive power, a third lens group G3 having positive refractive power, and a fourth lens group G4 having positive refractive power. The fourth lens group includes, in order from the object side, a 4a-th partial lens group having positive refractive power and a 4b-th partial lens group having negative refractive power. The fourth-a partial lens group has a negative meniscus lens turning its convex surface to the object side. Then, the camera shake correction is performed by moving the fourth-b partial lens group in a direction perpendicular to an optical axis.;COPYRIGHT: (C)2009,JPO&INPIT