Patent ID: 7738183

Claim:
A zoom lens comprising, in order from an object side to an image side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power, the second lens unit including a positive lens; and a third lens unit having a positive refractive power, wherein intervals between adjacent ones of the first lens unit, the second lens unit, and the third lens unit are variable during zooming, wherein a refractive power of a material of the positive lens included in the second lens unit (Nd 2 P) and an Abbe number of the material of the positive lens included in the second lens unit (νd 2 P) satisfy the following conditions: Nd 2 P+ 0.01 ×νd 2 P> 2.3 1.65<Nd2P<2.7 νd2P>45, and wherein a focal length of the positive lens included in the second lens unit (f 2 P) and a focal length of the second lens unit (f 2 ) satisfy the following condition: 0.37 <f 2 P/f 2<0.85.