A zoom lens comprising, disposed in order from an object side to an image surface
side, a negative-power first lens group, a diaphragm, a positive-power second lens
group, and a positive power third lens group, characterized in that, when zooming
from a wide-angle end to a telelscope end, an air gap between the first lens group
and the second lens group shrinks and an air gap between the second lens group
and the third lens group expands, the third lens group is movable in an optical
axis direction for focusing, and a zoom ratio at a shooting distance of
is 2.5- to 3.2-magnification.
