Patent ID: 8879162

Claim:
A zoom lens comprising, in order from its object side: a first lens unit having a negative refractive power; and a second lens unit having a positive refractive power, wherein the first lens unit comprises a first lens having a negative refractive power and a second lens having a positive refractive power, and the zoom lens satisfies the following conditional expressions (1), (2), and (3): n 1n ≦1.70 (1), n 1p ≦1.70 (2), and |ν 1n −ν 1p |≧31 (3), where n 1n is the refractive index of the first lens having a negative refractive power in the first lens unit for the d-line, ν 1n is the Abbe constant of the first lens having a negative refractive power in the first lens unit, n 1p is the refractive index of the second lens having a positive refractive power in the first lens unit for the d-line, and ν 1p is the Abbe constant of the second lens having a positive refractive power in the first lens unit, and wherein the zoom lens satisfies the following conditional expressions (5) and (6): d 1nw /d 1nc ≧3.0 (5), and f w /y≦ 1.4 (6), where d 1nw is the thickness of the first lens having a negative refractive power in the first lens unit at the position at which an outermost principal ray passes through it at the wide angle end, d 1nc is the thickness of the first lens having a negative refractive power in the first lens unit on the optical axis, and f w is the focal length of the zoom lens at the wide angle end.