Zoom lens system with vibration reduction function

An imaging apparatus including a zoom lens system which has a vibration reduction function and which comprises, in order from an object

• a first lens group having positive refractive power;
• a second lens group having negative refractive power;
• and
• a third lens group having positive refractive power,
• upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group increasing, and a distance between the second lens group and the third lens group decreasing,
• the third lens group comprising, in order from the object, a 31 lens group having positive refractive power, a 32 lens group having negative refractive power, and a 33 lens group,
• only the 32 lens group being moved in a direction perpendicular to an optical axis for correcting an image blur on an image plane upon generating a camera shake, and
• the following conditional expression being satisfied:
• 0.7<d31/d32<1.69
• where d31 denotes a distance between the 31 lens group and the 32 lens group, and d32 denotes a distance between the 32 lens group and the 33 lens group.

A method for forming an image of an object, varying a focal length, and correcting an image blur of a zoom lens system with a vibration reduction function, the method comprising steps of:

• providing a zoom lens system that includes, in order from an object, a first lens group having positive refractive power, a second lens group having negative refractive power, and a third lens group having positive refractive power;
• varying a focal length from a wide-angle end state to a telephoto end state by increasing a distance between the first lens group and the second lens group, and decreasing a distance between the second lens group and the third lens group;
• providing the third lens group that comprises, in order from the object, a 31 lens group having positive refractive power, a 32 lens group having negative refractive power, and a 33 lens group;
• satisfying the following conditional expression:
• 0.7<d31/d32<1.69
• where d31 denotes a distance between the 31 lens group and the 32 lens group, and d32 denotes a distance between the 32 lens group and the 33 lens group;
• and
• correcting an image blur on an image plane upon generating a camera shake by moving only the 32 lens group in a direction perpendicular to an optical axis.