Zoom lens and image pickup apparatus having the zoom lens

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;
• a third lens unit having a positive refractive power;
• and
• a rear lens unit including one or more lens units,
• wherein, during zooming, an interval between respective adjacent lens units varies such that an interval between the first lens unit and the second lens unit is larger at a telephoto end than at a wide-angle end and an interval between the second lens unit and the third lens unit is smaller at the telephoto end than at the wide-angle end,
• wherein the third lens unit includes at least one negative lens, and
• wherein, when νd3n and θgF3n are respectively an Abbe number and a relative partial dispersion of a material of the at least one negative lens of the third lens unit, the following conditions are satisfied:
• (−1.68×10−3×νd3n+0.570)<θgF3n<(3.15×10−4×νd3n2−1.86×10−2×νd3n+0.878),
• 5<νd3n<27.