A zoom lens includes 10 or less lens elements and having a zoom ratio of
more than 20.times., said zoom lens having first, second, third, and
fourth groups of lens elements placed in turn from object side to image
side; wherein the first group of lens elements has positive refractive
power and is fixed in position during zooming; wherein the second group
of lens elements has negative refractive power and is moved in position
during zooming; wherein the third group of lens elements has positive
refractive power, includes at least one aspheric surface, and is fixed in
position during zooming; wherein the fourth group of lens elements has
positive refractive power, includes at least one aspheric surface,
corrects variations in image surface position during zooming, and
performs focusing; and wherein the zoom lens satisfies the following
conditional expression (1):<< ##EQU00001## where dz is the movable
distance of the second group of lens elements to perform zooming and fw
is the focal distance of the whole lens system at a wide angle end.