The zoom lens consists of, in order from an object side, a positive first lens group, a negative second lens group, a positive third lens group, a stop, and a negative fourth lens group. During zooming, the second and third lens groups move. The fourth lens group consists of, in order from the object side, a fourth A lens group, a negative fourth B lens group moving during image blur correction, a positive fourth C lens group, and a negative fourth D lens group moving during focusing, and a positive fourth E lens group. The zoom lens satisfies predetermined conditional expressions.

A variable magnification optical system comprising, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a rear lens group having negative refractive power; upon varying a magnification from a wide angle end state to a tele photo end state, a distance between the first lens group and the second lens group being varied, a distance between the second lens group and the third lens group being varied, and a distance between the third lens group and the rear lens group being varied; the third lens group or the rear lens group comprising a focusing lens group which is moved upon carrying out focusing from an infinitely distant object to a closely distant object; and predetermined conditional expression(s) being satisfied, thereby various aberrations being corrected superbly.

A zoom optical system (ZL) comprises, in order from an object: a first lens group (G1) having a positive refractive power; a second lens group (G2) having a negative refractive power; a third lens group (G3) having a positive refractive power; and a subsequent lens group (GR), wherein upon zooming, a distance between the first lens group (G1) and the second lens group (G2) changes, a distance between the second lens group (G2) and the third lens group (G3) changes, and a distance between the third lens group (G3) and the subsequent lens group (GR) changes, the subsequent lens group (GR) comprises a focusing lens group that moves upon focusing, and the second lens group (G2) comprises a partial group that satisfies following conditional expressions, 1.40<fvr/f2<2.30, 1.80<f1/fw<3.50 where fvr: a focal length of the partial group, f2: a focal length of the second lens group (G2), f1: a focal length of the first lens group (G1), and fw: a focal length of the zoom optical system (ZL) in a wide-angle end state.

A zoom optical system comprises, in order from an object: a front lens group (GFS) having a positive refractive power; an M1 lens group (GM1) having a negative refractive power; an M2 lens group (GM2) having a positive refractive power; and an RN lens group (GRN) having a negative refractive power, wherein upon zooming, distances between the front lens group and the M1 lens group, between the M1 lens group and the M2 lens group, and between the M2 lens group and the RN lens group change, upon focusing from an infinite distant object to a short distant object, the RN lens group moves, and the M2 lens group comprises an A lens group that satisfies a following conditional expression, 1.10<fvr/fTM2<2.00, where, fvr: a focal length of the A lens group, and fTM2: a focal length of the M2 lens group in a telephoto end state.

A zoom optical system (ZL) comprises, in order from an object: a first lens group (G1) having a positive refractive power; a second lens group (G2) having a negative refractive power; a third lens group (G3) having a positive refractive power; and a subsequent lens group (GR), wherein upon zooming, a distance between the first lens group (G1) and the second lens group (G2) changes, a distance between the second lens group (G2) and the third lens group (G3) changes, and a distance between the third lens group (G3) and the subsequent lens group (GR) changes, the subsequent lens group (GR) comprises a focusing lens group that moves upon focusing, and the second lens group (G2) comprises a partial group that satisfies following conditional expressions, 1.40<fvr/f2<2.30, 1.80<f1/fw<3.50 where fvr: a focal length of the partial group, f2: a focal length of the second lens group (G2), f1: a focal length of the first lens group (G1), and fw: a focal length of the zoom optical system (ZL) in a wide-angle end state.

A zoom lens consists of, 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 unit that includes a plurality of lens units. All lens units move during zooming, and a distance between adjacent lens units changes. The third lens unit includes, in order from the object side to the image side, a first subunit having a positive refractive power, a second subunit having a positive refractive power, and a third subunit having a positive refractive power. The second subunit includes a negative lens and a positive lens. The second subunit moves in a direction having a component orthogonal to an optical axis during an image stabilization. A predetermined condition is satisfied.

A zoom lens consists of, in order from an object side to an image side, a front lens unit, intermediate and rear groups. The front lens unit has positive refractive power. The intermediate group includes a plurality of lens units and has a negative combined focal length at a wide-angle end. The rear group includes, in order from the object side to the image side, a first rear lens unit having positive refractive power, a second rear lens unit having negative refractive power, and a third rear lens unit having positive refractive power, and a fourth rear lens unit having negative refractive power. A distance between adjacent lens units changes during zooming. During zooming, the front lens unit, the first rear lens unit, and the third rear lens unit are fixed relative to an image plane. During focusing, the second rear lens unit moves relative to the image plane.

The present disclosure is directed to an optical system internally having an intermediate imaging position that is conjugate to magnification and reduction conjugate points, respectively, the optical system including: a magnification optical system having a plurality of lens elements, positioned on the magnification side with respect to the intermediate imaging position; and a relay optical system having a plurality of lens elements, positioned on the reduction side with respect to the intermediate imaging position, wherein there are a plurality of air distances among the lens elements, the magnification optical system includes a magnification optical system front group positioned on the magnification side with respect to the longest air distance in the magnification optical system and a magnification optical system rear group positioned on the reduction side with respect to the longest air distance, and the optical system satisfies the conditions (1) and (2).

A zoom optical system comprises, in order from an object: a front lens group (GFS) having a positive refractive power; an M1 lens group (GM1) having a negative refractive power; an M2 lens group (GM2) having a positive refractive power; and an RN lens group (GRN) having a negative refractive power, wherein upon zooming, distances between the front lens group and the M1 lens group, between the M1 lens group and the M2 lens group, and between the M2 lens group and the RN lens group change, upon focusing from an infinite distant object to a short distant object, the RN lens group moves, and the M2 lens group comprises an A lens group that satisfies a following conditional expression, 1.10<fvr/fTM2<2.00, where, fvr: a focal length of the A lens group, and fTM2: a focal length of the M2 lens group in a telephoto end state.

A variable magnification optical system comprising, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, and a rear lens group; upon varying magnification, the first lens group being fixed with respect to the image plane and each distance between the neighboring lens groups being varied; the rear lens group comprising a focusing lens group which is moved upon carrying out focusing; and the predetermined conditional expressions being satisfied, whereby it is possible to suppress superbly variations in aberrations upon varying the magnification.