Zoom lens and imaging apparatus

An imaging apparatus comprising:

• a zoom lens including a combination of only three lens groups;
• and
• an imaging device that converts an optical image, which is formed by the zoom lens, into an electric signal,
• wherein the combination of only three lens groups includes, in order from an object side to an image side,
• a first lens group which has a negative refractive power,
• a second lens group which has a positive refractive power, and
• a third lens group which has a positive refractive power,
• wherein the second lens group is disposed directly between the first and third lens groups,
• wherein the first lens group includes a single compound aspheric lens formed of a spherical glass lens which has a negative refractive power and a resin lens which has a positive refractive power and whose image side surface is formed to be aspheric,
• wherein the following conditional expressions (1) to (4) are satisfied
• f11/fw<−1.8, (1)
• 1.55<n11, (2)
• 55<ν11, and (3)
• G1r1<−16.5, (4)
• where
• f11 is a focal length of the spherical glass lens in the first lens group,
• fw is a focal length of the whole lens system at a wide-angle end,
• n11 is a refractive index of the spherical glass lens in the first lens group at the d-line,
• ν11 is an Abbe number of the spherical glass lens in the first lens group at the d-line, and
• G1r1 is a radius of curvature of an object side surface of the spherical glass lens in the first lens group.