Abstract: A zoom lens system includes, in order from object-side to image-side a positive first lens unit, a second negative lens unit, a third lens unit, and a fourth positive lens unit. The fourth unit includes a front subunit having positive power and a rear subunit having positive power. The following conditions are satisfied: ?2.100×10?3×?d+0.693<?gF; 0.555<?gF<0.900; 0.8<(?fp/?fn)/(?rp/?rn)<4.0; 0.

Abstract: A zoom lens comprises, 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, and a fourth lens unit having a positive refractive power. The fourth lens unit includes a forty-first lens unit having a negative refractive power and arranged at the object side with reference to the longest air gap and a forty-second lens unit having a positive refractive power and arranged at the image side with reference to the air gap. The forty-first lens unit includes a negative 411st lens, and the forty-second lens unit includes a positive 421st lens. Abbe numbers and partial dispersion ratios of materials of the 411st lens and the 421st lens ?d411, ?gF411, ?d421 and ?gF421 are appropriately set.

Abstract: A zoom lens comprises, 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, and a fourth lens unit having a positive refractive power. The fourth lens unit includes a forty-first lens unit having a negative refractive power and arranged at the object side with reference to the longest air gap and a forty-second lens unit having a positive refractive power and arranged at the image side with reference to the air gap. The forty-first lens unit includes a negative 411st lens, and the forty-second lens unit includes a positive 421st lens. Abbe numbers and partial dispersion ratios of materials of the 411st lens and the 421st lens ?d411, ?gF411, ?d421 and ?gF421 are appropriately set.

Abstract: A zoom lens system including, in order from object-side to image-side: a positive first lens unit, a second negative lens unit, a third lens unit and a fourth positive lens units, in which: the fourth unit includes a front subunit having positive power and a rear subunit having positive power; the following conditions are satisfied: ?2.100×10?3×?d+0.693<?gF, 0.555<?gF<0.900, where ?d and ?gF indicate Abbe number and partial dispersion ratio of a lens included in the rear subunit, respectively; 0.8<(?fp/?fn)/(?rp/?rn)<4.0, 0.