Zoom lens and image pickup apparatus including the same

An image pickup apparatus, comprising a zoom lens,

• wherein the zoom lens comprises, in order from an object side to an image side:
• a first lens unit having a positive refractive power that does not move for zooming, the first lens unit comprising a first sub-lens unit having a negative refractive power, a second sub-lens unit having a positive refractive power that moves during adjustment of a focal point, and a third sub-lens unit having a positive refractive power;
• a lens group including at least two lens units that move during zooming;
• an aperture stop;
• and
• a last lens unit having a positive refractive power that does not move for zooming,
• wherein the following conditional expressions are satisfied:
• 2.6<f1/fw<4.5
• 0.6<|f11/f1|<0.9
• 0.0<|βr|<1.5
• where fw denotes a focal length at a wide angle end of the zoom lens, f1 denotes a focal length of the first lens unit, f11 denotes a focal length of the first sub-lens unit, and βr denotes imaging magnification of the last lens unit,
• wherein the third sub-lens unit comprises at least one negative lens, and at least two positive lenses,
• wherein the following conditional expression is satisfied:
• 2.0<ν13pa/ν13na<5.8
• where ν13na denotes an average value of an Abbe constant with a d-line as a reference of the at least one negative lens, and ν13pa denotes an average value of Abbe constants with the d-line as the reference of the at least two positive lenses, and
• wherein an Abbe constant νd with the d-line as the reference is defined by the following equation:
• νd=(nd−1)/(nF−nC)
• where nd denotes a refractive index in the d-line, nC denotes a refractive index in a C-line, and nF denotes a refractive index in an F-line.