Patent ID: 8441738

Claim:
A zoom lens comprising: in order from an object side to an image side, a first lens unit having a positive refractive power; a second lens unit having a negative refractive power; and a rear group including one or more lens units, wherein an aperture stop is included on the image side of the second lens unit, and the second lens unit and at least one of the lens units included in the rear group move during zooming, and when an Abbe number and a partial dispersion ratio of a material of a refractive optical element j 1 having a negative refractive power included in the second lens unit are defined as νdj 1 and θgFj 1 respectively, a focal length of the refractive optical element j 1 is defined as fj 1 , a focal length of the second lens unit is defined as f 2 , and an anomalous partial dispersion ratio ΔθgFj 1 of the refractive optical element j 1 is calculated as ΔθgFj 1 =θgFj 1 −(−0.001682νdj 1 +0.6438), conditional expressions below are satisfied: 0 <θgFj 1−(−1.7×10 −7 ×νdj 1 3 +5.3×10 −5 ×νdj 1 2 −5.7×10 −3 ×νdj 1+0.76)<0.4, and 0.5×10 −3 <ΔθgFj 1/ν dj 1 ×f 2 /fj 1<2.0×10 −3 .