Patent ID: 7995283

Claim:
A zoom lens, comprising, in order from a magnifying side: a first lens unit having a negative refractive power; a second lens unit having a positive refractive power; and a rear lens group, which includes multiple lens units and has a positive refractive power as a whole, wherein at least two lens units are moved for magnification, wherein a whole lens system of the zoom lens comprises the first lens unit, the second lens unit, and the rear lens group, wherein the first lens unit includes a first lens having a negative refractive power, and wherein the following conditions are satisfied: 0.79 <θgF NL −(1.0×10 −r ×νd NL 2 −9.1×10 −3 ×νd NL )<1.00, 1.5<( R 1+ R 2)/( R 1− R 2)<10.0, and 0.0005<|(Δθ gF NL ·fw )/(ν d NL ·f NL )|<0.0020, where R1 and R2 indicate a magnifying side curvature radius and a reduction side curvature radius of the first lens, θgF NL indicates a partial dispersion ratio of the first lens with respect to a g-line and an F-line, νd NL indicates an Abbe number of the first lens, f NL indicates a focal length of the first lens, and fw indicates a focal length of the whole lens system at a wide angle end, and where Δθ gF NL =θgF NL −(−0.001682 ×νd NL +0.6438).