Abstract: A zoom lens includes a first lens unit having a positive refracting power and is fixed during zooming, a second lens unit having a negative refracting power and is movable during zooming, a third lens unit having a positive refracting power and used to correct the image surface by the zooming, and a fourth lens unit having a positive refracting power. These lens units are arranged in the order named from the object side. In order to properly correct halo/coma that tends to occur during zooming, an aspherical surface is formed in the third lens unit at a focal length fm given by fm=fw·z½, where fw is the wide-angle focal length, and z is the zoom ratio, when the imaging magnifications of the second and third lens units simultaneously pass through −1-time point during zooming.

Abstract: A zoom lens including, in succession from the object side, a first positive lens unit (focal length f1), a second negative lens unit, a third lens unit, and a fourth positive lens unit, the second and third lens units moving for zooming, the first lens unit having, from the object side, a front lens subunit (focal length f11) fixed during focusing and a rear lens subunit (focal length f12) movable toward the object side for focusing on an infinity object to a short distance object, the front lens subunit having a cemented lens comprising a first negative lens (refractive power N111, Abbe number .nu.111) and a second positive lens (refractive power N112, Abbe number .nu.112) cemented together, the rear lens subunit having first and second positive lenses, wherein, where Ri is the radius of curvature of the ith lens surface from the object side:f/11/f1<-100.85<f12/f1<1.1-1.77<(R2+R1)/(R2-R1)<-1.150.45<(R3+R2)/(R3-R2)<0.9-0.7<(R3+R1)/(R3-R1)<0.20.25<N111-N11240<.vertline..nu.

Abstract: A zoom lens is disclosed comprising, from front to rear, a first lens unit of positive refractive power, a second lens unit of negative refractive power, a flare cut stop for cutting a lower marginal ray of an off-axial bundle of rays for a maximum image height, a third lens unit of positive refractive power and a fourth lens unit of positive refractive power, wherein the second and third lens units move axially to effect zooming, while either varying the aperture diameter of the flare cut stop or axially moving the flare cut stop to thereby cut the harmful rays for good optical performance.