It is an object to provide a zoom lens made of three groups having a zoom ratio
of 2.5 to 3.2 if the object distance is , an field angle at
the wide-angle end of 60 to 70, high resolution, and a short optical
total length when not in use. The zoom lens is made of a first lens group (G1)
with a negative power, a second lens group (G2) with a positive power, and
a third lens group (G3) with a positive power, arranged in that order from
an object side to an image plane (S) side. The first lens group (G1) is
made of a first lens (L1) that is a negative meniscus lens whose surface
with strong curvature is facing the image plane (S) side and a second lens (L2)
that is a positive meniscus lens whose surface with strong curvature is facing
the object side, arranged in that order from the object side. The second lens group
(G2) is made of a third lens (L3) that is a positive lens whose convex
surface is facing the object side, a fourth lens (L4) that is a positive
lens, a fifth lens (L5) that is a negative lens, and a sixth lens (L6)
that is a plano-convex lens whose convex surface is facing the image plane (S)
side, arranged in that order from the object side. The third lens group (G3)
is made of a single seventh lens (L7) that is a positive lens.