Patent ID: 7525729

Claim:
A zoom lens having, in an order of an object-to-image direction, a first lens group having a positive refractive power and is fixed with respect to an image plane; a second lens group having a negative refractive power and is for zooming by moving on an optical axis; a third lens group having a positive refractive power and is fixed with respect to an optical axis direction; a fourth lens group having a positive refractive power and is for correcting fluctuations in imaging position by moving on the optical axis, as well as for correcting an imaging position change associated with a change in object distance; and a fifth lens group having a positive refractive power and is fixed with respect to the optical axis direction, wherein: the fifth lens group is composed of, in the order of the object-to-image direction, a fifth-a lens group having a negative refractive power; a fifth-b lens group having a positive refractive power; and a fifth-c lens group having a positive refractive power, the fifth-a lens group is composed of, in the order of the object-to-image direction, two negative lenses which are of a first negative lens having a powerful concave surface facing toward an image, and a second negative lens having a powerful concave surface facing toward an object, a shift of the image is provided by shifting the fifth-b lens group so as to have a perpendicular component with respect to the optical axis, and a conditional expression (1) shown below is satisfied: −4.0< f 5 c/f 5 a<− 1.5 (1) where f 5 a is a focal length of the fifth-a lens group, and f 5 c is focal length of the fifth-c lens group.