Patent ID: 8228614

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 subsequent lens unit including at least two lens units, wherein an interval between respective adjacent lens units varies for zooming, wherein the first lens unit includes: a positive lens; and a negative lens, wherein a deviation, from a standard line, of a material of a negative lens GLn, whose relative partial dispersion of a material (θgF) is the lowest of relative partial dispersions of materials of other lenses included in the first lens unit (ΔθgF 1 n ), an Abbe number of the material of the negative lens GLn (ν 1 n ), a focal length of the negative lens GLn (f 1 n ), a deviation, from a standard line, of a material of a positive lens GNLp, whose relative partial dispersion of a material (θgF) is the highest of relative partial dispersions of materials of other lenses included in the first lens unit (ΔθgF 1 p ), an Abbe number of the material of the positive lens GNLp (ν 1 p ), a focal length of the positive lens GNLp (f 1 p ), and a focal length of the entire zoom lens at a telephoto end (ft) satisfy the following conditions: −4.5<( ft/f 1 n )×(Δθ gF 1 n/ν 1 n )×10 4 <6.0 5.0<ν1 n< 27.0 5.5<( ft/f 1 p )×(Δθ gF 1 p/ν 1 p )×10 4 <25.0.