Zoom lens system and image pickup apparatus including the same

Abstract

A zoom lens system, includes, in order from an object side to an image side: a positive first lens unit which does not move for zooming; a negative second lens unit which moves for zooming; a positive third lens unit which moves for zooming; and a fourth lens unit which does not move for zooming, is provided for imaging, and has a positive refractive power, in which the third lens unit includes multiple lenses including a positive lens and a negative lens, and the third lens unit satisfies: −2.0×10<(θpa−θna)/(νpa−νna)<−1.4×10; and 41<νpa−νna<53; and 2.9<SGa3<3.2, where νna and θna indicate averages of Abbe number and partial dispersion ratio respectively, of the negative lenses, νpa and θpa indicate an average Abbe number of the positive lenses of the positive lenses included therein, respectively, and SGa3 indicates an average specific gravity of the lenses.