A zoom lens includes, in order from an object side, a first lens group G1 having a positive focal length, a second lens group G2 having a negative focal length, a third lens group G3 including an aperture stop S and having a positive focal length, a fourth lens group G4 having a negative focal length, and a rear side lens group G5. The first lens group includes a negative lens and a positive lens disposed in order from a most object side. The first lens group and the third lens group are fixed in power varying from a wide angle end to a telephoto end. The second lens group moves from the object side to an image side in the power varying. The zoom lens satisfies following conditional expressions (1) and (2).

2.1≤F1/Fw≤3.0   (1)

−1.2≤F3/F2≤−0.8  (2)

The present disclosure is directed to an optical system internally having an intermediate imaging position that is conjugated to a magnification conjugate point on a magnification side and a reduction conjugate point on a reduction side, respectively, the optical system comprising: a magnification optical system positioned on the magnification side with respect to the intermediate imaging position; and a relay optical system positioned on the reduction side with respect to the intermediate imaging position; the relay optical system including: a first lens group positioned closest to the magnification side; two lens groups positioned on the reduction side with respect to the first lens group; and a negative lens group interposed between the two lens groups, wherein during zooming the negative lens is fixed, while the two lens groups are displaced.

A zoom lens ZL includes: a first lens unit L1 having a positive refractive power, a second lens unit L2 having a negative refractive power, and a third lens unit L3 having a positive refractive power, an N−1th lens unit, and an Nth lens unit, the lens units being arranged in order from an object side to an image side. The N−1th lens unit and the Nth lens unit are located on the image side with respect to an aperture stop SP.

A zoom lens consists of, in order from the object side, a first lens group that has a positive refractive power, a middle group that includes a plurality of lens groups in which the spacings between adjacent lens groups change during zooming, and the final lens group. The focusing group that moves during focusing is disposed in the middle group. The zoom lens satisfies predetermined conditional expressions.

An optical system having high optical performance, an optical apparatus including the optical system, and a method for manufacturing the optical system are provided. An optical system used for an optical apparatus such as a camera includes a front lens group including a diffraction lens having a diffraction surface and a rear lens group disposed on an image side of the front lens group. The optical system is configured so that an interval between the lens groups changes at magnification change. The optical system is also configured so that a condition expressed by a predetermined conditional expression is satisfied.

A zoom optical system comprises, in order from an object side: a first lens group having positive refractive power; a front-side lens group; an intermediate lens group having positive refractive power; and a rear-side lens group. The front-side lens group is composed of one or more lens groups and has a negative lens group. At least part of the intermediate lens group is a focusing lens group. The rear-side lens group is composed of one or more lens groups. Upon zooming, distances between the first lens group and the front-side lens group, between the front-side lens group and the intermediate lens group, and between the intermediate lens group and the rear-side lens group change. The following conditional expressions are satisfied:

−10.000<fF/fRF<10.000

0.010<|fF/fXR|<10.000

where fF denotes a focal length of the focusing lens group, fRF denotes a focal length of a lens group closest to the object side in the rear-side lens group, and fXR denotes a focal length of a lens group closet to an image surface in the front-side lens group.

A zoom optical system consists of, in order from an object on an optical axis: a first lens group having a positive refractive power; a second lens group having a negative refractive power; and a rear group that includes a plurality of lens groups. The rear group comprises a first focusing lens group having a positive refractive power, and a second focusing lens group having a negative refractive power. Upon zooming from a wide angle end to a telephoto end, distances between lens groups adjacent to each other among the first lens group, the second lens group, and the plurality of lens groups, change. Upon focusing from an infinity object to a short distance object, the first focusing lens group and the second focusing lens group move toward an image along movement trajectories different from each other. The following conditional expression is satisfied,

1.10<f2/fF2<2.00

where f2: a focal length of the second lens group, and

fF2: a focal length of the second focusing lens group.

An optical system includes a movable unit movable in a direction eccentric to an optical axis. The movable unit includes a resin layer and a lens cemented together and satisfies a predetermined condition.

A zoom lens includes, in order from an object side: a first lens group having positive power; a second lens group having negative power; a third lens group having positive power; a fourth lens group having positive power; a fifth lens group having negative power; and a sixth lens group having positive power. The fourth lens group includes at least one positive lens that satisfies a conditional formula of vdp≥65. A conditional formula of 1.19≤f3/ft≤4.15 and a conditional formula of 0.51≤f4/ft≤1.50 are satisfied.

This variable power optical system (ZL(1)) has a plurality of lens groups (G1-G7), and the intervals between the respectively adjacent lens groups change during power variation. The plurality of lens groups include a first focusing lens group (G6) that moves during focusing, and a second focusing lens group (G7) that is disposed closer to the image surface than is the first focusing lens group and moves so as to follow a track different from that of the first focusing lens group. The first focusing lens group (G6) and the second focusing lens group (G7) each have a negative refractive power and satisfy conditional expression: 0.40<MTF1/MTF2<1.00, where MTF1 represents an absolute value of the movement amount of the first focusing lens group during shifting, in a telephoto end state, from an object-at-infinity focusing state to an object-at-extremely-close-distance focusing state, and MTF2 represents an absolute value of the movement amount of the second focusing lens group during shifting, in a telephoto end state, from the object-at-infinity focusing state to the object-at-extremely-close-distance focusing state.