A zoom lens includes a first lens group having a negative refractive
power, and second and third lens groups each having a positive refractive
power, sequentially aligned from an object side. The first lens group is
moved along an optical axis and the second lens group is moved along the
optical axis toward the object side, during zooming from a wide-angle end
state to a telescopic end state. The third lens group includes a negative
sub-lens group having a negative refractive power, and a positive
sub-lens group having a positive refractive power, sequentially aligned
from the object side. Moving the positive sub-lens group orthogonally to
the optical axis causes image shifting. The zoom lens satisfies a
conditional expression (1): 0.3<1-.beta.<2.5, where .beta. is a
magnification of the positive sub-lens group at the telescopic end state.