A zoom lens, including, in order from an object side to an image side (a)
a first lens unit of negative optical power, (b) a second lens unit of
positive optical power, and (c) a third lens unit of positive optical
power, wherein a separation between the first lens unit and the second
lens unit and a separation between the second lens unit and the third
lens unit are varied to effect variation of magnification, and wherein
the zoom lens satisfies the following conditions: ndp3<1.5 and
vdp3>70.0, where ndp3 and vdp3 are a refractive index and Abbe number,
respectively, of material of the positive lens in the third lens unit.