Zoom lens and image pickup apparatus

A zoom lens comprising, in order from an object side to an image side:

• a first lens unit with positive refractive power which does not move for zooming;
• and
• a plurality of lens units which moves in zooming, each of intervals between the respective adjacent lens units varying in zooming,
• wherein the plurality of lens units includes a variable magnification unit consisting of one or a plurality of lens units which monotonously moves toward the image side in zooming from a wide-angle end to a telephoto end,
• wherein the variable magnification unit includes at least one positive lens and at least one negative lens and has negative refractive power at the wide-angle end,
• wherein the zoom lens satisfies the following inequality:
• −0.040<θCtVpav−θCtVnav<0.040,
• where θCtVpav denotes an average value of partial dispersion ratios regarding C-line and t-line of all of the positive lenses included in the variable magnification unit and θCtVnav denotes an average value of partial dispersion ratios regarding C-line and t-line of all of the negative lenses included in the variable magnification unit, and
• wherein the variable magnification unit includes a positive lens satisfying the following inequalities:
• 0.5466<θCtVpx−0.004693×vdVpx<0.6466, and
• 24<vdVpx<55,
• where vdVpx denotes an Abbe number regarding d-line of the positive lens included in the variable magnification unit and θCtVpx denotes a partial dispersion ratio regarding C-line and t-line of the positive lens included in the variable magnification unit.