A zoom lens system having an exit pupil far away from the image plane, zoom ratio
of about three, and in particular having compactness and high optical performance
includes, in order from an object, a first lens group having negative refractive
power, an aperture stop, a second lens group having positive refractive power,
and a third lens group having positive refractive power. When zooming from a wide-angle
end state to a telephoto end state, the first and second lens groups are moved
and the third lens group is fixed such that a distance between the first lens group
and the second lens group varies, and a distance between the second lens group
and the third lens group increases. The second lens group is composed of four lenses
or less and includes a diffractive optical surface formed on a lens surface except
the most object side lens surface.
