Variable power optical system, optical device and manufacturing process for variable power optical system

Description

TECHNICAL FIELD

[0001] The present invention relates to a zoom optical system and an optical apparatus using the zoom optical system,TECHNICAL BACKGROUND

[0002] Conventionally, a zoom optical system equipped with a vibration proof group for correcting image blur has been proposed (see, for example, Japanese Laid-Open Patent Publication No. 11-316342 (A), hereinafter Patent Literature 1). However, in a zoom optical system equipped with a vibration proof group, a wider angle of view is required. Also, in a zoom optical system equipped with a vibration proof group, a higher zooming rate is required. Also, in a zoom optical system equipped with a vibration proof group, achieving a small size of the vibration proof group is required.

[0003] Each of US 20110205636 A1, JP 2011 099924 A, US 2014 / 347525 A1, US 2013 / 242171 A1, WO 2016 / 017727 A1, and US 2017 / 192212 A1 forms part of the state of the art relative to the present disclosure.SUMMARY OF THE INVENTION

[0004] According to a first aspect of the present invention, there is provided a zoom optical system as recited in claim 1 below.

[0005] According to a second aspect of the present invention, there is provided an optical apparatus as recited in claim 21 below.

[0006] The dependent claims define particular embodiments of each respective aspect.

[0007] The present disclosure also provides a method of manufacturing the optical system of the first aspect.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] FIG. 1 is a drawing illustrating a lens configuration of a zoom optical system according to Example 1; FIG. 2A, FIG. 2B and FIG. 2C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 1; FIG. 3A, FIG. 3B, and FIG. 3C are each an aberration graph illustrating aberrations upon focusing on a short distant object in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 1; FIG. 4A, FIG. 4B, and FIG. 4C are each a meridional lateral (or transverse) aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 1; FIG. 5 is a drawing illustrating a lens configuration of a zoom optical system according to Example 2; FIG. 6A, FIG. 6B and FIG. 6C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 2; FIG. 7A, FIG. 7B, and FIG. 7C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 2; FIG. 8A, FIG. 8B, and FIG. 8C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 2; FIG. 9 is a drawing illustrating a lens configuration of a zoom optical system according to Example 3; FIG. 10A, FIG. 10B, and FIG. 10C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 3; FIG. 11A, FIG. 11B and FIG. 11C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 3; FIG. 12A, FIG. 12B, and FIG. 12C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 3; FIG. 13 is a drawing illustrating a lens configuration of a zoom optical system according to Example 4; FIG. 14A, FIG. 14B, and FIG. 14C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 4; FIG. 15A, FIG. 15B, and FIG. 15C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 4; FIG. 16A, FIG. 16B, and FIG. 16C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 4; FIG. 17 is a drawing illustrating a lens configuration of a zoom optical system according to Example 5; FIG. 18A, FIG. 18B, and FIG. 18C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 5; FIG. 19A, FIG. 19B, and FIG. 19C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 5; FIG. 20A, FIG. 20B, and FIG. 20C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 5; FIG. 21 is a drawing illustrating a lens configuration of a zoom optical system according to Example 6; FIG. 22A, FIG. 22B, and FIG. 22C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 6; FIG. 23A, FIG. 23B, and FIG. 23C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 6; FIG. 24A, FIG. 24B, and FIG. 24C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 6; FIG. 25 is a drawing illustrating a lens configuration of a zoom optical system according to Example 7; FIG. 26A, FIG. 26B, and FIG. 26C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 7; FIG. 27A, FIG. 27B, and FIG. 27C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 7; FIG. 28A, FIG. 28B, and FIG. 28C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 7; FIG. 29 is a drawing illustrating a lens configuration of a zoom optical system according to an Example 8; FIG. 30A, FIG. 30B, and FIG. 30C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 8; FIG. 31A, FIG. 31B, and FIG. 31C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 8; FIG. 32A, FIG. 32B, and FIG. 32C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 8; FIG. 33 is a drawing illustrating a lens configuration of a zoom optical system according to Example 9; FIG. 34A, FIG. 34B, and FIG. 34C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 9; FIG. 35A, FIG. 35B, and FIG. 35C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 9; FIG. 36A, FIG. 36B, and FIG. 36C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 9; FIG. 37 is a drawing illustrating a lens configuration of a zoom optical system according to Example 10; FIG. 38A, FIG. 38B, and FIG. 38C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 10; FIG. 39A, FIG. 39B, and FIG. 39C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 10; FIG. 40A, FIG. 40B, and FIG. 40C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 10; FIG. 41 is a drawing illustrating a lens configuration of a zoom optical system according to an Example 11; FIG. 42A, FIG. 42B, and FIG. 42C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 11; FIG. 43A, FIG. 43B, and FIG. 43C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 11; FIG. 44A, FIG. 44B, and FIG. 44C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 11; FIG. 45 is a drawing illustrating a lens configuration of a zoom optical system according to Example 12; FIG. 46A, FIG. 46B, and FIG. 46C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 12; FIG. 47A, FIG. 47B, and FIG. 47C are each an aberration graph illustrating aberrations upon focusing on a short distant object in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system according to Example 12; FIG. 48A, FIG. 48B, and FIG. 48C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system according to Example 12; FIG. 49 is a drawing illustrating a configuration of a camera provided with the zoom optical system; FIG. 50 is a flowchart illustrating a method for manufacturing a zoom optical system; FIG. 51 is a flowchart illustrating a method for manufacturing a zoom optical system; and FIG. 52 is a flowchart illustrating a method for manufacturing a zoom optical system For a better understanding of the present invention and how the same may be carried into effect, Fig. 13, Fig. 21, Fig. 25, Fig. 29, Fig. 33, Fig. 37, Fig. 41 and Fig. 45 are indicated all to be embodiments of the claimed invention. Other disclosed and depicted configurations are exemplary and illustrative. The scope of the invention is defined by the appended claims, and is not restricted to the illustrated embodiments.DETAILED DESCRIPTION

[0012] (First Configuration )

[0009] A zoom optical system and an optical apparatus according to a first configuration will now be described with reference to the drawings. A zoom optical system ZL (1) as an example of the zoom optical system (zoom lens) ZL according to the first configuration includes: as illustrated in FIG. 1, a first negative lens group (second lens group G2) having a negative refractive power, and a second negative lens group (fourth lens group G4) disposed closer to an image than the first negative lens group. During zooming, a distance between the first negative lens group and the second negative lens group changes. At least part of the first negative lens group is movable so as to have a displacement component in a direction perpendicular to an optical axis. At least part of the second negative lens group is movable along the optical axis during focusing.

[0010] The zoom optical system ZL according to the first configuration may be a zoom optical system ZL (2) illustrated in FIG. 5, may be a zoom optical system ZL (3) illustrated in FIG. 9; may be a zoom optical system ZL (4) illustrated in FIG. 13; may be a zoom optical system ZL (5) illustrated in FIG. 17; and may be a zoom optical system ZL (6) illustrated in FIG. 21. The zoom optical system ZL of the first configuration may be a zoom optical system ZL (7) illustrated in FIG. 25; may be a zoom optical system ZL (8) illustrated in FIG. 29; may be a zoom optical system ZL (9) illustrated in FIG. 33; may be a zoom optical system ZL (10) illustrated in FIG. 37; and may be a zoom optical system ZL (11) illustrated in FIG. 41. It should be noted that groups from the zoom optical system ZL (2) to ZL (11) illustrated in FIG. 5 or other drawings are configured in the same manner as the zoom optical system ZL (1) illustrated in FIG. 1.

[0011] The zoom optical system ZL according to the first configuration having the configuration described above satisfies the following conditional expression. Accordingly, an optical performance in a wide angle end state is improved, and thus a telephoto type zoom optical system having a wider angle of view is achieved. In addition, by adjusting the power of the second negative lens group while balancing the powers of the first negative lens group and the second negative lens group, a zoom optical system suitable for imaging a video is achieved. 0.50 < fGb / fGa < 2.60 where, fGa : a focal length of the first negative lens group, and fGb : a focal length of the second negative lens group.

[0012] The conditional expression (1) is a conditional expression for defining an adequate range for a ratio of focal lengths between the second negative lens group (fourth lens group G4) and the first negative lens group (second lens group G2). When a corresponding value of the conditional expression (1) exceeds an upper limit value, the power (refractive power) of the first negative lens group is too much stronger than the power of the second negative lens group, which makes it difficult to correct spherical aberration and coma aberration in the telephoto end state. In order to ensure the effect of this configuration , the upper limit value of the conditional expression (1) is preferably set to 2.40, and more preferably to 2.10.

[0013] When the corresponding value of the conditional expression (1) undergoes a lower limit value, the power of the second negative lens group is too much stronger than the power of the first negative lens group, which makes it difficult to correct astigmatism in the wide angle end state and spherical aberration in the telephoto end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (1) is preferably set to 0.60, and more preferably to 0.70.

[0014] In the zoom optical system ZL according to the first configuration, the first negative lens group (second lens group G2) preferably includes at least partly a vibration proof group movable so as to have a displacement component in a direction perpendicular to an optical axis, and satisfies the following conditional expression (2). 0.93 < fVR / fGa < 2.50 where fVR : a focal length of the vibration proof group.

[0015] The conditional expression (2) is a conditional expression for defining an adequate range for a ratio of focal lengths between the vibration proof group and the first negative lens group (second lens group G2). By satisfying the conditional expression (2), correction of the eccentric coma aberration and the eccentric curvature of field when the shake compensation is performed may be successfully corrected. Also, the lateral chromatic aberration and the distortion in the wide angle end state may be successfully corrected. In addition, the power of the first negative lens group is secured without increasing the power of the vibration proof group too much so that a zooming rate may be gained. For example, a zooming rate of three times or more, preferably, a zooming rate of four times of more may be achieved.

[0016] When a corresponding value of the conditional expression (2) exceeds an upper limit value, the power of the first negative lens group is too much stronger than the power of the vibration proof group, which makes it difficult to correct lateral chromatic aberration and distortion in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (2) is preferably set to 2.10, and more preferably to 1.70.

[0017] When the corresponding value of the conditional expression (2) undergoes the lower limit value, the power of the vibration proof group is too much stronger than the power of the first negative lens group, which makes it difficult to correct the eccentric coma aberration and the eccentric curvature of field when shake compensation is performed. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (2) is preferably set to 1.00.

[0018] In the zoom optical system ZL according to the first configuration, the second negative lens group (fourth lens group G4) preferably comprises a positive lens and a negative lens which are disposed in order from an object, and an air distance is present between the positive lens and the negative lens, and satisfies the following conditional expression (3). 0.001 < Dpn / − fGb < 0.400 where Dpn : an air distance between the positive lens and the negative lens in the second negative lens group.

[0019] The conditional expression (3) is a conditional expression for defining an adequate range for an air distance between the positive lens and the negative lens in the second negative lens group (fourth lens group G4). By satisfying the conditional expression (3), a successful aberration correction is achieved. In addition, since manufacture sensitivity of the second negative lens group is lowered, the zoom optical system ZL is easily manufactured.

[0020] When the corresponding value of the conditional expression (3) exceeds the upper limit value, the air distance between the positive lens and the negative lens in the second negative lens group increases, which makes it difficult to correct the astigmatism in the wide angle end state. In order to ensure the effect of this configuration , the upper limit value of the conditional expression (3) is preferably set to 0.300, and more preferably to 0.200.

[0021] When the corresponding value of the conditional expression (3) undergoes the lower limit value, the air distance between the positive lens and the negative lens in the second negative lens group decreases, which makes it difficult to correct the coma aberration in the telephoto end state. In order to ensure the effect of this configuration , the lower limit value of the conditional expression (3) is preferably set to 0.003, and more preferably to 0.005.

[0022] In the zoom optical system ZL according to the first configuration, the first negative lens group (second lens group G2) may include at least partly a vibration proof group movable so as to have a displacement component in a direction perpendicular to an optical axis, the vibration proof group may consist of a positive lens, a first negative lens, and a second negative lens disposed in order from an object, an air distance may be present between the positive lens and the first negative lens, and an air distance may be present between the first negative lens and the second negative lens. Accordingly, the eccentric coma aberration and the eccentric curvature of field when the shake compensation is performed may be successfully corrected. Also, the lateral chromatic aberration and the distortion in the wide angle end state may be successfully corrected. Also, in the vibration proof group, a positive lens is disposed on an object side with respect to the first negative lens and the second negative lens, and thus reduction in diameter of the vibration proof group is enabled.

[0023] Preferably, the zoom optical system ZL according to the first configuration includes: an intermediate lens group (third lens group G3) disposed between the first negative lens group (second lens group G2) and the second negative lens group (fourth lens group G4), and the distance between the first negative lens group and the intermediate lens group changes, and the distance between the intermediate lens group and the second negative lens group changes during zooming. Accordingly, the distance between the first negative lens group and the intermediate lens group changes, and the distance between the intermediate lens group and the second negative lens group changes during zooming, and thus a high zooming rate is obtained.

[0024] Preferably, the zoom optical system ZL according to the first configuration includes: an object side lens group (first lens group G1) disposed on the object side with respect to the first negative lens group (second lens group G2) and having a positive refractive power, and the distance between the object side lens group and the first negative lens group changes during zooming. Accordingly, the distance between the object side lens group and the first negative lens group changes during zooming, and thus a high zooming rate is achieved.

[0025] Preferably, the zoom optical system ZL according to the first configuration includes: an image side lens group (fifth lens group G5) disposed closer to an image than the second negative lens group (fourth lens group G4), and the distance between the second negative lens group and the image side lens group changes during zooming. Accordingly, the distance between the second negative lens group and the image side lens group changes during zooming, and thus a high zooming rate is achieved.

[0026] Preferably, the zoom optical system ZL according to the first configuration includes: an intermediate lens group (third lens group G3) disposed between the first negative lens group (second lens group G2) and the second negative lens group (fourth lens group G4), and the distance between the first negative lens group and the intermediate lens group changes, and the distance between the intermediate lens group and the second negative lens group changes during zooming, and an aperture stop S is disposed between the first negative lens group and the intermediate lens group. Accordingly, the astigmatism, the coma aberration, and the lateral chromatic aberration may be successfully corrected.

[0027] Preferably, the zoom optical system ZL according to the first configuration includes: an intermediate lens group (third lens group G3) disposed between the first negative lens group (second lens group G2) and the second negative lens group (fourth lens group G4), and the distance between the first negative lens group and the intermediate lens group changes, and the distance between the intermediate lens group and the second negative lens group changes during zooming, and the intermediate lens group consists of the object side subgroup having a positive refractive power and the image side subgroup having a positive refractive power disposed in order from an object, and when a lens component including a negative lens is disposed at a position closest to the object in the image side subgroup (in each example of the following description, the object side subgroup and the image side subgroup in such a case are referred to as first object side subgroup and first image side subgroup), the following conditional expression (4) is satisfied. 0.06 < fa / fb < 1.20 where fa : a focal length of object side subgroup, and fb : a focal length of image side subgroup.

[0028] The conditional expression (4) is a conditional expression for defining an adequate range for a ratio of focal lengths between the object side subgroup and the image side subgroup of the intermediate lens group (third lens group G3). By satisfying the conditional expression (4), the axial chromatic aberration and the spherical aberration are successfully corrected. It should be noted that, in each configuration, the lens component indicates a single lens or a cemented lens.

[0029] When the corresponding value of the conditional expression (4) exceeds the upper limit value, the power of the image side subgroup is too much stronger than the power of the object side subgroup, which makes it difficult to correct the axial chromatic aberration. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (4) is preferably set to 1.00, and more preferably to 0.80.

[0030] When the corresponding value of the conditional expression (4) undergoes the lower limit value, the power of the object side subgroup is too much stronger than the power of the image side subgroup, which makes it difficult to correct the spherical aberration. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (4) is preferably set to 0.08, and more preferably to 0.10.

[0031] Preferably, the zoom optical system ZL according to the first configuration includes: an intermediate lens group (third lens group G3) disposed between the first negative lens group (second lens group G2) and the second negative lens group (fourth lens group G4), and the distance between the first negative lens group and the intermediate lens group changes, and the distance between the intermediate lens group and the second negative lens group changes during zooming, and the intermediate lens group consists of the object side subgroup having a positive refractive power and the image side subgroup having a positive refractive power disposed in order from an object, and when the air distance between the object side subgroup and the image side subgroup is the maximum air distance between the air distance between lenses in the intermediate lens group, (in each example of the following description, the object side subgroup and the image side subgroup in such a case are referred to as second object side subgroup and second image side subgroup), the following conditional expression (5) is satisfied. 0.06 < fα / fβ < 2.60 where fα : a focal length of object side subgroup, and fβ : a focal length of image side subgroup.

[0032] The conditional expression (5) is a conditional expression for defining an adequate range for a ratio of focal lengths between the object side subgroup and the image side subgroup of the intermediate lens group (third lens group G3). By satisfying the conditional expression (5), the axial chromatic aberration and the spherical aberration are successfully corrected.

[0033] When the corresponding value of the conditional expression (5) exceeds the upper limit value, the power of the image side subgroup is too much stronger than the power of the object side subgroup, which makes it difficult to correct the axial chromatic aberration. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (5) is preferably set to 2.20, and more preferably to 1.80.

[0034] When the corresponding value of the conditional expression (5) undergoes the lower limit value, the power of the object side subgroup is too much stronger than the power of the image side subgroup, which makes it difficult to correct the spherical aberration. In order to ensure the effect of this configuration , the lower limit value of the conditional expression (5) is preferably set to 0.08, and more preferably to 0.10.

[0035] In the zoom optical system ZL according to the first configuration , the first negative lens group (second lens group G2) may include partly a vibration proof group movable so as to have a displacement component in a direction perpendicular to an optical axis, the first negative lens group may consist of a negative subgroup having a negative refractive power and the vibration proof group described above and having a negative refractive power disposed in order from an object, and a lens component including a positive lens may be disposed at a position closest to the image in the vibration proof group. Accordingly, the eccentric coma aberration and the eccentric curvature of field when the shake compensation is performed may be successfully corrected. Also, the lateral chromatic aberration and the distortion in the wide angle end state may be successfully corrected.

[0036] Preferably, the zoom optical system ZL according to the first configuration includes: an intermediate lens group (third lens group G3) disposed between the first negative lens group (second lens group G2) and the second negative lens group (fourth lens group G4), and the distance between the first negative lens group and the intermediate lens group changes, and the distance between the intermediate lens group and the second negative lens group changes during zooming, and the following conditional expression (6) is satisfied. 0.40 < fGc / − fGa < 2.60 where, fGc : a focal length of an intermediate lens group.

[0037] The conditional expression (6) is a conditional expression for defining an adequate range for a ratio of focal lengths between the intermediate lens group (third lens group G3) and the first negative lens group (second lens group G2). When a corresponding value of the conditional expression (6) exceeds an upper limit value, the power of the first negative lens group is too much stronger than the power of the intermediate lens group, which makes it difficult to correct the astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (6) is preferably set to 2.20, and more preferably to 1.80.

[0038] When a corresponding value of the conditional expression (6) undergoes a lower limit value, the power of the intermediate lens group is too much stronger than the power of the first negative lens group, which makes it difficult to correct the astigmatism in the telephoto end state. In order to ensure the effect of this configuration , the lower limit value of the conditional expression (6) is preferably set to 0.55, and more preferably to 0.70.

[0039] Preferably, the zoom optical system ZL according to the first configuration includes: an intermediate lens group (third lens group G3) disposed between the first negative lens group (second lens group G2) and the second negative lens group (fourth lens group G4), and the distance between the first negative lens group and the intermediate lens group changes, and the distance between the intermediate lens group and the second negative lens group changes during zooming, and the following conditional expression (7) is satisfied. 0.20 < fGc / − fGb < 2.40 where, fGc : a focal length of an intermediate lens group.

[0040] The conditional expression (7) is a conditional expression for defining an adequate range for a ratio of focal lengths between the intermediate lens group (third lens group G3) and the second negative lens group (fourth lens group G4). When a corresponding value of the conditional expression (7) exceeds an upper limit value, the power of the second negative lens group is too much stronger than the power of the intermediate lens group, which makes it difficult to correct the coma aberration in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (7) is preferably set to 2.00, and more preferably to 1.60.

[0041] When a corresponding value of the conditional expression (7) undergoes a lower limit value, the power of the intermediate lens group is too much stronger than the power of the second negative lens group, which makes it difficult to correct the astigmatism in the telephoto end state. In order to ensure the effect of this configuration , the lower limit value of the conditional expression (7) is preferably set to 0.30, and more preferably to 0.40.

[0042] Preferably, the zoom optical system ZL according to the first configuration includes: an object side lens group (first lens group G1) disposed on the object side with respect to the first negative lens group (second lens group G2) and having a positive refractive power, and the distance between the object side lens group and the first negative lens group changes during zooming, and the following conditional expression (8) is satisfied. 0.30 < mda / fw < 2.30 where |mda| : an absolute value of the amount of change in distance from a lens surface closest to an image in the object side lens group to a lens surface closest to an object in the first negative lens group on the optical axis during zooming from the wide angle end state to the telephoto end state, and fw : a focal length of the zoom optical system ZL in the wide angle end state.

[0043] The conditional expression (8) is a conditional expression for defining an adequate range for variable magnification burden of the first negative lens group (second lens group G2). When the corresponding value of the conditional expression (8) exceeds the upper limit value, the amount of change (absolute value) in distance between the object side lens group (first lens group G1) and the first negative lens group (second lens group G2) increases. Therefore, the variable magnification burden of the first negative lens group increases, which makes it difficult to correct the coma aberration and the curvature of field. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (8) is preferably set to 1.90, and more preferably to 1.50.

[0044] When the corresponding value of the conditional expression (8) undergoes the lower limit value, the amount of change (absolute value) in distance between the object side lens group and the first negative lens group is too small to secure a high zooming rate. In order to secure a zooming rate in a state in which the corresponding value of the conditional expression (8) undergoes the lower limit value, the power of the first negative lens group needs to be stronger, which makes it difficult to correct the spherical aberration and the coma aberration. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (8) is preferably set to 0.40, and more preferably to 0.50.

[0045] Preferably, the zoom optical system ZL according to the first configuration includes: an intermediate lens group (third lens group G3) disposed between the first negative lens group (second lens group G2) and the second negative lens group (fourth lens group G4), and the distance between the first negative lens group and the intermediate lens group changes, and the distance between the intermediate lens group and the second negative lens group changes during zooming, and the following conditional expression (9) is satisfied. 0.050 < mcb / fw < 0.750 where |mcb| : an absolute value of the amount of change in distance from a lens surface closest to an image in the intermediate lens group to a lens surface closest to an object in the second negative lens group on the optical axis during zooming from the wide angle end state to the telephoto end state, and fw : a focal length of the zoom optical system ZL in the wide angle end state.

[0046] The conditional expression (9) is a conditional expression for achieving both the variable magnification burden and the aberration correction effect of the second negative lens group (fourth lens group G4). When the corresponding value of the conditional expression (9) exceeds the upper limit value, the amount of change (absolute value) in distance between the intermediate lens group (third lens group G3) and the second negative lens group (fourth lens group G4) increases. Therefore, the variable magnification burden of the second negative lens group increases, which makes it difficult to correct spherical aberration in the telephoto end state and astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (9) is preferably set to 0.650, and more preferably to 0.550.

[0047] When the lower limit value of the corresponding value of the conditional expression (9) undergoes the lower limit value, the amount of change (absolute value) in distance between the intermediate lens group and the second negative lens group decreases, and thus the aberration correction effect of change in distance between the intermediate lens group and the second negative lens group is less likely achieved. Therefore, achievement of both the aberration correction in the telephoto end state and the aberration correction in the wide angle end state is difficult, which makes it difficult to correct the spherical aberration and astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (9) is preferably set to 0.065, and more preferably to 0.080.

[0048] Preferably, the zoom optical system ZL according to the first configuration includes: an aperture stop S disposed between the first negative lens group (second lens group G2) and the second negative lens group (fourth lens group G4), and a lens group (third lens group G3) having a positive lens component disposed so as to oppose the image side of the aperture stop S, and a distance between the first negative lens group and a lens group having a positive lens component changes, a distance between the lens group having the positive lens component and the second negative lens group changes during zooming, and the following conditional expression (10) is satisfied. 0.40 < fp / fGp < 3.60 where fp : a focal length of the positive lens component, and fGp : a focal length of the lens group having the positive lens component.

[0049] The conditional expression (10) is a conditional expression defining an adequate range of a focal length of the positive lens component disposed so as to oppose the image side of the aperture stop S. When the corresponding value of the conditional expression (10) exceeds the upper limit value, the power of the positive lens component decreases, which makes it difficult to correct the spherical aberration and the coma aberration. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (10) is preferably set to 3.00, and more preferably to 2.60.

[0050] When the corresponding value of the conditional expression (10) undergoes the lower limit value, the power of the positive lens component increases, and thus, which is advantageous for correction of various aberrations such as spherical aberration as a representative example. However, it is not preferable because deterioration of optical performance becomes prominent when the positive lens component is deviated due to assembly accuracy at the time of manufacture. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (10) is preferably set to 0.50, and more preferably to 0.60.

[0051] Preferably, the zoom optical system ZL according to the first configuration includes: an aperture stop S disposed between the first negative lens group (second lens group G2) and the second negative lens group (fourth lens group G4), and a lens group (third lens group G3) having a positive lens component disposed so as to oppose the image side of the aperture stop S, and a distance between the first negative lens group and a lens group having a positive lens component changes, a distance between the lens group having the positive lens component and the second negative lens group changes during zooming, and the following conditional expression (11) is satisfied. 0.40 < LS / LGp < 0.90 where LS : a sum of air distances on the image side of the positive lens component in the lens group having the positive lens component, and LGp : a thickness of the lens group having the positive lens component on the optical axis.

[0052] The conditional expression (11) is a conditional expression defining an adequate range of the thickness of the lens group having the positive lens component on the optical axis. When the corresponding value of the conditional expression (11) exceeds the upper limit value, the power of the lens surface closer to an image than the positive lens component becomes stronger in the lens group having the positive lens component, which makes it difficult to correct the coma aberration in the telephoto end state and the astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (11) is preferably set to 0.80, and more preferably to 0.70.

[0053] When the corresponding value of the conditional expression (11) undergoes the lower limit value, the power of the lens surface closer to an image than the positive lens component becomes weaker in the lens group having the positive lens component, which makes it difficult to correct the coma aberration in the telephoto end state and the astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (11) is preferably set to 0.42, and more preferably to 0.435.

[0054] Preferably, the zoom optical system ZL according to the first configuration includes: an aperture stop S disposed between the first negative lens group (second lens group G2) and the second negative lens group (fourth lens group G4), and a lens group (third lens group G3) having a positive lens component disposed so as to oppose the image side of the aperture stop S, and a distance between the first negative lens group and a lens group having a positive lens component changes, a distance between the lens group having the positive lens component and the second negative lens group changes during zooming, and at least one lens surface of the positive lens component has an aspherical surface, and the following conditional expression (12) is satisfied. 0.15 < 100 × Δ / φ < 1.30 where ϕ : a maximum effective diameter of the lens surface on the object side of the positive lens component, and Δ : an absolute value between a difference between the aspherical amount at a position corresponding to the maximum effective diameter of the lens surface on the object side in the positive lens component and the aspherical amount at a position corresponding to the maximum effective diameter of the lens surface on the image side in the positive lens component.

[0055] The conditional expression (12) is a conditional expression defining an adequate range of an aspherical amount (sag amount) of the positive lens component disposed so as to oppose the image side of the aperture stop S. It should be noted that the effective diameter of the lens surface on the object side in the positive lens component or the effective diameter of the lens surface on the image side becomes the maximum effective diameter upon focusing on infinity in the telephoto end state. However, the invention is not limited thereto. Also, the aspherical surface may be formed only on the lens surface on the object side of the positive lens component, may be formed only on the lens surface on the image side of the positive lens component, or may be formed on lens surfaces on both sides of the positive lens component. In other words, as described above, the aspherical surface needs only be formed on at least one of the lens surfaces of the positive lens component.

[0056] When the corresponding value of the conditional expression (12) exceeds the upper limit value, the aspherical amount of the positive lens component increases, and thus, which is advantageous for correction of various aberrations such as spherical aberration as a representative example. However, it is not preferable because deterioration of optical performance becomes prominent when the positive lens component is deviated due to assembly accuracy at the time of manufacture. In order to ensure the effect of this configuration , the upper limit value of the conditional expression (12) is preferably set to 1.00, and more preferably to 0.80.

[0057] When the corresponding value of the conditional expression (12) undergoes the lower limit value, the aspherical amount of the positive lens component decreases, which makes it difficult to correct the spherical aberration and the coma aberration. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (12) is preferably set to 0.20, and more preferably to 0.25.

[0058] An optical apparatus according to the first configuration is configured with the zoom optical system having a configuration described above. As a specific example, a camera (optical apparatus) provided with the zoom optical system ZL according to the first configuration will be described with reference to FIG. 49. The camera 1 is a digital camera provided with the zoom optical system according to the configuration described above as an imaging lens 2 as illustrated in FIG. 49. In this camera 1, light from an object (subject) not illustrated is converged by the imaging lens 2, and reaches an image pickup device 3. Accordingly, light from the subject is imaged by the image pickup device 3, and is recorded in a memory, not illustrated, as a subject image. A photographer is allowed to photograph the subject by the camera 1 in this manner. It should be noted that the camera may be a mirror-less camera, or may be a single lens reflex type camera having a quick return mirror. In this configuration, by mounting the zoom optical system ZL according to the first configuration as the imaging lens, an optical apparatus having an improved optical performance in the wide angle end state and having a wider angle of view is achieved.

[0059] Subsequently, an outline of a method for manufacturing the zoom optical system ZL according to the first configuration will be described with reference to FIG. 50. First, a first negative lens group (second lens group G2) having a negative refractive power and a second negative lens group (fourth lens group G4) closer to an image than the first negative lens group and having a negative refractive power are disposed in a lens barrel (Step ST1). It is configured that the distance between the first negative lens group and the second negative lens group is changed during zooming (Step ST2). At least part of the first negative lens group is configured to be movable so as to have a displacement component in a direction perpendicular to the optical axis, and at least part of the second negative lens group is configured to be movable along the optical axis during focusing (Step ST3). In addition, each lens is arranged within a lens barrel so as to satisfy at least the aforementioned conditional expression (1) (Step ST4). According to the manufacturing method as described above, the optical performance in a wide angle end state is improved, and thus a telephoto type zoom optical system having a wider angle of view may be manufactured.(Second configuration)

[0060] Next, a zoom optical system and an optical apparatus according to a second configuration will now be described with reference to the drawings. A zoom optical system ZL (1) as an example of the zoom optical system (zoom lens) ZL according to the second configuration comprises: as illustrated in FIG. 1, a first lens group G1 having a positive refractive power, a second lens group G2 disposed closer to an image than the first lens group G1 and having a negative refractive power, a third lens group G3 disposed closer to an image than the second lens group G2 and having a positive refractive power, and a fourth lens group G4 disposed closer to an image than the third lens group G3 and having a negative refractive power. A distance between the first lens group G1 and the second lens croup 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 fourth lens group G4 changes during zooming. The second lens group G2 may be configured to include at least partly a vibration proof group movable so as to have a displacement component in a direction perpendicular to an optical axis. The fourth lens group G4 is configured to include a positive lens and a negative lens disposed in order from an object. It should be noted that an air distance is present between the positive lens and the negative lens.

[0061] The zoom optical system ZL according to the second configuration may be a zoom optical system ZL (2) illustrated in FIG. 5, may be a zoom optical system ZL (3) illustrated in FIG. 9; may be a zoom optical system ZL (4) illustrated in FIG. 13; may be a zoom optical system ZL (5) illustrated in FIG. 17; and may be a zoom optical system ZL (6) illustrated in FIG. 21. Also, the zoom optical system ZL according to the second configuration may be a zoom optical system ZL (7) illustrated in FIG. 25; may be a zoom optical system ZL (8) illustrated in FIG. 29; may be a zoom optical system ZL (9) illustrated in FIG. 33; may be a zoom optical system ZL (10) illustrated in FIG. 37; and may be a zoom optical system ZL (11) illustrated in FIG. 41. It should be noted that groups from the zoom optical system ZL (2) to ZL (11) illustrated in FIG. 5 or other drawings are configured in the same manner as the zoom optical system ZL (1) illustrated in FIG. 1.

[0062] The zoom optical system ZL according to the second configuration having the configuration described above satisfies the following conditional expressions. Accordingly, a telephoto type zoom optical system having a higher zooming rate is achieved. 0.001 < Dpn / − f 4 < 0.400 0.93 < fVR / f 2 < 2.50 where Dpn : an air distance between the positive lens and the negative lens in the fourth lens group G4, f4 : a focal length of the fourth lens group G4, fVR : a focal length of the vibration proof group, and f2 : a focal length of the second lens group G2.

[0063] The conditional expression (13) is a conditional expression for defining an adequate range for an air distance between the positive lens and the negative lens in the fourth lens group G4. When the corresponding value of the conditional expression (13) exceeds the upper limit value, the air distance between the positive lens and the negative lens in the fourth lens group G4 increases, which makes it difficult to correct the astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (13) is preferably set to 0.300, and more preferably to 0.200.

[0064] When the corresponding value of the conditional expression (13) undergoes the lower limit value, the air distance between the positive lens and the negative lens in the fourth lens group G4 decreases, which makes it difficult to correct the coma aberration in the telephoto end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (13) is preferably set to 0.003, and more preferably to 0.005.

[0065] The conditional expression (14) is a conditional expression for defining an adequate range for a ratio of focal lengths between the vibration proof group and the second lens group G2. By satisfying the conditional expression (14), the eccentric coma aberration and the eccentric curvature of field when the shake compensation is performed may be successfully corrected. Also, the lateral chromatic aberration and the distortion in the wide angle end state may be successfully corrected.

[0066] When a corresponding value of the conditional expression (14) exceeds an upper limit value, the power of the second lens group G2 is too much stronger than the power of the vibration proof group, which makes it difficult to correct lateral chromatic aberration and distortion in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (14) is preferably set to 2.10, and more preferably to 1.70.

[0067] When the corresponding value of the conditional expression (14) undergoes the lower limit value, the power of the vibration proof group is too much stronger than the power of the second lens group G2, which makes it difficult to correct the eccentric coma aberration and the eccentric curvature of field when shake compensation is performed. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (14) is preferably set to 1.00.

[0068] Preferably, in the zoom optical system ZL according to the second configuration, during focusing, at least part of the lenses in the fourth lens group G4 move along the optical axis. Accordingly, variations in chromatic aberration and variation in spherical aberration during focusing may be successfully corrected.

[0069] Preferably, in the zoom optical system ZL according to the second configuration, the following conditional expression (15) is satisfied. 0.40 < f 4 / f 2 < 4.00 where f4 : a focal length of the fourth lens group G4, and f2 : a focal length of the second lens group G2.

[0070] The conditional expression (15) is a conditional expression for defining an adequate range for a ratio of focal lengths between the fourth lens group G4 and the second lens group G2. When a corresponding value of the conditional expression (15) exceeds an upper limit value, the power (refractive power) of the second lens group G2 is too much stronger than the power of the fourth lens group G4, which makes it difficult to correct spherical aberration and coma aberration in the telephoto end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (15) is preferably set to 3.25, and more preferably to 2.50.

[0071] When the corresponding value of the conditional expression (15) undergoes a lower limit value, the power of the fourth lens group G4 is too much stronger than the power of the second lens group G2, which makes it difficult to correct astigmatism in the wide angle end state and spherical aberration in the telephoto end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (15) is preferably set to 0.55, and more preferably to 0.70.

[0072] Preferably, in the zoom optical system ZL according to the second configuration, an aperture stop S is disposed between the second lens group G2 and the third lens group G3. Accordingly, the astigmatism, the coma aberration, and the lateral chromatic aberration may be successfully corrected.

[0073] Preferably, in the zoom optical system ZL according to the second configuration, when the third lens group G3 consists of an object side subgroup having a positive refractive power and an image side subgroup having a positive refractive power disposed in order from an object, and a lens component including the negative lens is disposed at a position closest to the object in the image side subgroup, (in each example of the following description, the object side subgroup and the image side subgroup in such a case are referred to as first object side subgroup and first image side subgroup), the following conditional expression (16) is satisfied. 0.06 < f 3 a / f 3 b < 1.20 where f3a : a focal length of object side subgroup, and f3b : a focal length of image side subgroup.

[0074] The conditional expression (16) is a conditional expression for defining an adequate range for a ratio of focal lengths between the object side subgroup and the image side subgroup in the third lens group G3. By satisfying the conditional expression (16), the axial chromatic aberration and the spherical aberration are successfully corrected.

[0075] When the corresponding value of the conditional expression (16) exceeds the upper limit value, the power of the image side subgroup is too much stronger than the power of the object side subgroup, which makes it difficult to correct the axial chromatic aberration. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (16) is preferably set to 1.00, and more preferably to 0.80.

[0076] When the corresponding value of the conditional expression (16) undergoes the lower limit value, the power of the object side subgroup is too much stronger than the power of the image side subgroup, which makes it difficult to correct the spherical aberration. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (16) is preferably set to 0.08, and more preferably to 0.10.

[0077] Preferably, in the zoom optical system ZL according to the second configuration, the third lens group G3 consists of the object side subgroup having a positive refractive power and the image side subgroup having a positive refractive power disposed in order from an object, and when the air distance between the object side subgroup and the image side subgroup is the maximum air distance between the distance between lenses in the third lens group G3, (in each example of the following description, the object side subgroup and the image side subgroup in such a case are referred to as second object side subgroup and second image side subgroup), the following conditional expression (17) is satisfied. 0.06 < f 3 α / f 3 β < 2.60 where f3α : a focal length of object side subgroup, and f3β : a focal length of image side subgroup.

[0078] The conditional expression (17) is a conditional expression for defining an adequate range for a ratio of focal lengths between the object side subgroup and the image side subgroup in the third lens group G3. By satisfying the conditional expression (17), the axial chromatic aberration and the spherical aberration are successfully corrected.

[0079] When the corresponding value of the conditional expression (17) exceeds the upper limit value, the power of the image side subgroup is too much stronger than the power of the object side subgroup, which makes it difficult to correct the axial chromatic aberration. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (17) is preferably set to 2.20, and more preferably to 1.80.

[0080] When the corresponding value of the conditional expression (17) undergoes the lower limit value, the power of the object side subgroup is too much stronger than the power of the image side subgroup, which makes it difficult to correct the spherical aberration. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (17) is preferably set to 0.08, and more preferably to 0.10.

[0081] In the zoom optical system ZL according to the second configuration, the second lens group G2 may consist of a negative subgroup having a negative refractive power and the vibration proof group described above and having a negative refractive power disposed in order from an object, and a lens component including a positive lens may be disposed at a position closest to the image in the vibration proof group. Accordingly, the eccentric coma aberration and the eccentric curvature of field when the shake compensation is performed may be successfully corrected. Also, the lateral chromatic aberration and the distortion in the wide angle end state may be successfully corrected.

[0082] In the zoom optical system ZL according to the second configuration, the vibration proof group may consist of a positive lens, a first negative lens, and a second negative lens disposed in order from an object, an air distance may be present between the positive lens and the first negative lens, and an air distance may be present between the first negative lens and the second negative lens. Accordingly, the eccentric coma aberration and the eccentric curvature of field when the shake compensation is performed may be successfully corrected. Also, the lateral chromatic aberration and the distortion in the wide angle end state may be successfully corrected.

[0083] Preferably, in the zoom optical system ZL according to the second configuration, the following conditional expression (18) is satisfied. 0.40 < f 3 / − f 2 < 2.60 where, f3 : a focal length of the third lens group G3, and f2 : a focal length of the second lens group G2.

[0084] The conditional expression (18) is a conditional expression for defining an adequate range for a ratio of focal lengths between the third lens group G3 and the second lens group G2. When a corresponding value of the conditional expression (18) exceeds an upper limit value, the power of the second lens group G2 is too much stronger than the power of the third lens group G3, which makes it difficult to correct the astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (18) is preferably set to 2.20, and more preferably to 1.80.

[0085] When a corresponding value of the conditional expression (18) undergoes a lower limit value, the power of the third lens group G3 is too much stronger than the power of the second lens group G2, which makes it difficult to correct the astigmatism in the telephoto end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (18) is preferably set to 0.55, and more preferably to 0.70.

[0086] Preferably, in the zoom optical system ZL according to the second configuration, the following conditional expression (19) is satisfied. 0.20 < f 3 / − f 4 < 2.40 where f3 : a focal length of the third lens group G3, and f4 : a focal length of the fourth lens group G4.

[0087] The conditional expression (19) is a conditional expression for defining an adequate range for a ratio of focal lengths between the third lens group G3 and the fourth lens group G4. When a corresponding value of the conditional expression (19) exceeds an upper limit value, the power of the fourth lens group G4 is too much stronger than the power of the third lens group G3, which makes it difficult to correct the coma aberration in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (19) is preferably set to 2.00, and more preferably to 1.60.

[0088] When a corresponding value of the conditional expression (19) undergoes a lower limit value, the power of the third lens group G3 is too much stronger than the power of the fourth lens group G4, which makes it difficult to correct the astigmatism in the telephoto end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (19) is preferably set to 0.30, and more preferably to 0.40.

[0089] Preferably, in the zoom optical system ZL according to the second configuration, the following conditional expression (20) is satisfied. 0.30 < m 12 / fw < 2.30 where, |m12| : an absolute value of the amount of change in distance from a lens surface closest to an image in the first lens group G1 to a lens surface closest to an object in the second lens group G2 on the optical axis during zooming from the wide angle end state to the telephoto end state, and fw : a focal length of the zoom optical system ZL in the wide angle end state.

[0090] The conditional expression (20) is a conditional expression for defining an adequate range for variable magnification burden of the second lens group G2. When the corresponding value of the conditional expression (20) exceeds the upper limit value, the amount of change (absolute value) in distance between the first lens group G1 and the second lens group G2 increases. Therefore, the variable magnification burden of the second lens group G2 increases, which makes it difficult to correct the coma aberration and the curvature of field. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (20) is preferably set to 1.90, and more preferably to 1.50.

[0091] When the corresponding value of the conditional expression (20) undergoes the lower limit value, the amount of change (absolute value) in distance between the first lens group G1 and the second lens group G2 is too small to secure a high zooming rate. In order to secure a zooming rate in a state in which the corresponding value of the conditional expression (20) undergoes the lower limit value, the power of the second lens group G2 needs to be stronger, which makes it difficult to correct the spherical aberration and the coma aberration. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (20) is preferably set to 0.40, and more preferably to 0.50.

[0092] Preferably, in the zoom optical system ZL according to the second configuration, the following conditional expression (21) is satisfied. 0.050 < m 34 / fw < 0.750 where |m34| : an absolute value of the amount of change in distance from a lens surface closest to an image in the third lens group G3 to a lens surface closest to an object in the fourth lens group G4 on the optical axis during zooming from the wide angle end state to the telephoto end state, and fw : a focal length of the zoom optical system ZL in the wide angle end state.

[0093] The conditional expression (21) is a conditional expression for achieving both the variable magnification burden and the aberration correction effect of the fourth lens group G4. When the corresponding value of the conditional expression (21) exceeds the upper limit value, the amount of change (absolute value) in distance between the third lens group G3 and the fourth lens group G4 increases. Therefore, the variable magnification burden of the fourth lens group G4 increases, which makes it difficult to correct spherical aberration in the telephoto end state and astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (21) is preferably set to 0.650, and more preferably to 0.550.

[0094] When the lower limit value of the corresponding value of the conditional expression (21) undergoes the lower limit value, the amount of change (absolute value) in distance between the third lens group G3 and the fourth lens group G4 decreases, and thus the aberration correction effect of change in distance between the third lens group G3 and the fourth lens group G4 is less likely achieved. Therefore, achievement of both the aberration correction in the telephoto end state and the aberration correction in the wide angle end state is difficult, which makes it difficult to correct the spherical aberration and astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (21) is preferably set to 0.065, and more preferably to 0.080.

[0095] An optical apparatus according to the second configuration is configured with the zoom optical system having a configuration described above. As a specific example, a camera (optical apparatus) provided with the zoom optical system ZL according to the second configuration will be described with reference to FIG. 49. The camera 1 is a digital camera provided with the zoom optical system according to the configuration described above as an imaging lens 2 as illustrated in FIG. 49. In this camera 1, light from an object (subject) not illustrated is converged by the imaging lens 2, and reaches an image pickup device 3. Accordingly, light from the subject is imaged by the image pickup device 3, and is recorded in a memory, not illustrated, as a subject image. A photographer is allowed to photograph the subject by the camera 1 in this manner. It should be noted that the camera may be a mirror-less camera, or may be a single lens reflex type camera having a quick return mirror. In this configuration, by mounting the zoom optical system ZL according to the second configuration as the imaging lens, an optical apparatus having a higher zooming rate is achieved.

[0096] Subsequently, an outline of a method for manufacturing the zoom optical system ZL according to the second configuration will be described with reference to FIG. 51. First, in a lens barrel, the first lens group G1 having a positive refractive power, the second lens group G2 closer to an image than the first lens group G1 and having a negative refractive power, the third lens group G3 closer to an image than the second lens group G2 and having a positive refractive power, and the fourth lens group G4 closer to an image than the third lens group G3 and having a negative refractive power are arranged (Step ST11). Then, it is configured that 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 the distance between the third lens group G3 and the fourth lens group G4 changes during zooming (Step ST12). Also, a vibration proof group movable so as to have a displacement component in a direction perpendicular to an optical axis is provided on at least part of the second lens group G2. Further, in the fourth lens group G4, a positive lens and a negative lens are arranged in order from an object and an air distance is present between the positive lens and the negative lens (Step ST13). In addition, each lens is arranged within a lens barrel so as to satisfy at least the aforementioned conditional expression (13) and the conditional expression (14) (Step ST14). With such a manufacturing method, a telephoto type zoom optical system having a higher zooming rate is manufactured.(Third configuration)

[0097] Next, a zoom optical system and an optical apparatus according to a third configuration will now be described with reference to the drawings. A zoom optical system ZL (9) as an example of the zoom optical system (zoom lens) ZL according to the third configuration comprises: as illustrated in FIG. 33, a first lens group G1 having a positive refractive power, a second lens group G2 disposed closer to an image than the first lens group G1 and having a negative refractive power, a third lens group G3 disposed closer to an image than the second lens group G2 and having a positive refractive power, and a following group GR disposed closer to an image than the third lens group G3 and consisting of at least one lens group (fourth lens group G4 and fifth lens group G5). 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 following group GR changes during zooming.

[0098] Any one of the first lens group G1, the second lens group G2, the third lens group G3, and the following group GR is configured to include a vibration proof group movable so as to have a displacement component in a direction perpendicular to an optical axis. The vibration proof group consists of a positive lens, a first negative lens, and a second negative lens disposed in order from an object. It should be noted that an air distance is present between the positive lens and the first negative lens, and an air distance is present between the first negative lens and the second negative lens. Accordingly, a telephoto type zoom optical system having a small-sized vibration proof group is achieved.

[0099] The zoom optical system ZL according to the third configuration may be a zoom optical system ZL (10) illustrated in FIG. 37; may be a zoom optical system ZL (11) illustrated in FIG. 41; and may be a zoom optical system ZL (12) illustrated in FIG. 45. It should be noted that groups from the zoom optical system ZL (10) to ZL (12) illustrated in FIG. 37 or other drawings are configured in the same manner as the zoom optical system ZL (9) illustrated in FIG. 33.

[0100] Preferably, in the zoom optical system ZL according to the third configuration, the second lens group G2 consists of the aforementioned vibration proof group. Accordingly, the eccentric coma aberration and the eccentric curvature of field when the shake compensation is performed may be successfully corrected. Also, the lateral chromatic aberration and the distortion in the wide angle end state may be successfully corrected.

[0101] Preferably, in the zoom optical system ZL according to the third configuration, the following group GR includes a fourth lens group G4 disposed closer to an image than the third lens group G3, and at least part of lenses in the fourth lens group G4 moves along the optical axis during focusing. Accordingly, variations in chromatic aberration and variation in spherical aberration during focusing may be successfully corrected.

[0102] Preferably, in the zoom optical system ZL according to the third configuration, the following group GR includes a fourth lens group G4 disposed closer to an image than the third lens group G3, and the following conditional expression (22) is satisfied. 0.40 < f 4 / − f 2 < 4.00 where, f4 : a focal length of the fourth lens group G4, and f2 : a focal length of the second lens group G2.

[0103] The conditional expression (22) is a conditional expression for defining an adequate range for a ratio of focal lengths between the fourth lens group G4 and the second lens group G2. When a corresponding value of the conditional expression (22) exceeds an upper limit value, the power (refractive power) of the second lens group G2 is too much stronger than the power of the fourth lens group G4, which makes it difficult to correct spherical aberration and coma aberration in the telephoto end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (22) is preferably set to 3.30, and more preferably to 2.70.

[0104] When the corresponding value of the conditional expression (22) undergoes a lower limit value, the power of the fourth lens group G4 is too much stronger than the power of the second lens group G2, which makes it difficult to correct astigmatism in the wide angle end state and spherical aberration in the telephoto end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (22) is preferably set to 0.60, and more preferably to 0.80.

[0105] Preferably, in the zoom optical system ZL according to the third configuration, an aperture stop S is disposed between the second lens group G2 and the third lens group G3. Accordingly, the astigmatism, the coma aberration, and the lateral chromatic aberration may be successfully corrected.

[0106] Preferably, in the zoom optical system ZL according to the third configuration, the third lens group G3 consists of the object side subgroup having a positive refractive power and the image side subgroup having a positive refractive power disposed in order from an object, and when a lens component including a negative lens is disposed at a position closest to the object in the image side subgroup, (in each example of the following description, the object side subgroup and the image side subgroup in such a case are referred to as first object side subgroup and first image side subgroup), the following conditional expression (23) is satisfied. 0.08 < f 3 a / f 3 b < 1.20 where, f3a : a focal length of object side subgroup, and f3b : a focal length of image side subgroup.

[0107] The conditional expression (23) is a conditional expression for defining an adequate range for a ratio of focal lengths between the object side subgroup and the image side subgroup in the third lens group G3. By satisfying the conditional expression (23), the axial chromatic aberration and the spherical aberration are successfully corrected. In this configuration, the lens component indicates a single lens or a cemented lens.

[0108] When the corresponding value of the conditional expression (23) exceeds the upper limit value, the power of the image side subgroup is too much stronger than the power of the object side subgroup, which makes it difficult to correct the axial chromatic aberration. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (23) is preferably set to 1.00, and more preferably to 0.80.

[0109] When the corresponding value of the conditional expression (23) undergoes the lower limit value, the power of the object side subgroup is too much stronger than the power of the image side subgroup, which makes it difficult to correct the spherical aberration. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (23) is preferably set to 0.09, and more preferably to 0.10.

[0110] Preferably, in the zoom optical system ZL according to the third configuration, the third lens group G3 consists of the object side subgroup having a positive refractive power and the image side subgroup having a positive refractive power disposed in order from an object, and when the air distance between the object side subgroup and the image side subgroup is the maximum air distance between the air distance between lenses in the third lens group G3, (in each example of the following description, the object side subgroup and the image side subgroup in such a case are referred to as second object side subgroup and second image side subgroup), the following conditional expression (24) is satisfied. 0.04 < f 3 α / f 3 β < 1.40 where, f3α : a focal length of object side subgroup, and f3β : a focal length of image side subgroup.

[0111] The conditional expression (24) is a conditional expression for defining an adequate range for a ratio of focal lengths between the object side subgroup and the image side subgroup in the third lens group G3. By satisfying the conditional expression (24), the axial chromatic aberration and the spherical aberration are successfully corrected.

[0112] When the corresponding value of the conditional expression (24) exceeds the upper limit value, the power of the image side subgroup is too much stronger than the power of the object side subgroup, which makes it difficult to correct the axial chromatic aberration. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (24) is preferably set to 1.15, and more preferably to 0.90.

[0113] When the corresponding value of the conditional expression (24) undergoes the lower limit value, the power of the object side subgroup is too much stronger than the power of the image side subgroup, which makes it difficult to correct the spherical aberration. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (24) is preferably set to 0.05, and more preferably to 0.06.

[0114] Preferably, in the zoom optical system ZL according to the third configuration, the following group GR includes a fourth lens group G4 disposed closer to an image than the third lens group G3, and the fourth lens group G4 includes a positive lens and a negative lens disposed in order from an object, and an air distance is present between the positive lens and the negative lens. Accordingly, variations in chromatic aberration and variation in spherical aberration during focusing may be successfully corrected.

[0115] Preferably, in the zoom optical system ZL according to the third configuration, the following conditional expression (25) is satisfied. 0.40 < f 3 / − f 2 < 2.60 where, f3 : a focal length of the third lens group G3, and f2 : a focal length of the second lens group G2.

[0116] The conditional expression (25) is a conditional expression for defining an adequate range for a ratio of focal lengths between the third lens group G3 and the second lens group G2. When a corresponding value of the conditional expression (25) exceeds an upper limit value, the power of the second lens group G2 is too much stronger than the power of the third lens group G3, which makes it difficult to correct the astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (25) is preferably set to 2.20, and more preferably to 1.80.

[0117] When a corresponding value of the conditional expression (25) undergoes a lower limit value, the power of the third lens group G3 is too much stronger than the power of the second lens group G2, which makes it difficult to correct the astigmatism in the telephoto end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (25) is preferably set to 0.55, and more preferably to 0.70.

[0118] Preferably, in the zoom optical system ZL according to the third configuration, the following group GR includes a fourth lens group G4 disposed closer to an image than the third lens group G3, and the following conditional expression (26) is satisfied. 0.10 < f 3 / f 4 < 1.50 where, f3 : a focal length of the third lens group G3, and f4 : a focal length of the fourth lens group G4.

[0119] The conditional expression (26) is a conditional expression for defining an adequate range for a ratio of focal lengths between the third lens group G3 and the fourth lens group G4. When a corresponding value of the conditional expression (26) exceeds an upper limit value, the power of the fourth lens group G4 is too much stronger than the power of the third lens group G3, which makes it difficult to correct the coma aberration in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (26) is preferably set to 1.25, and more preferably to 1.00.

[0120] When a corresponding value of the conditional expression (26) undergoes a lower limit value, the power of the third lens group G3 is too much stronger than the power of the fourth lens group G4, which makes it difficult to correct the astigmatism in the telephoto end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (26) is preferably set to 0.20, and more preferably to 0.30.

[0121] Preferably, in the zoom optical system ZL according to the third configuration, the following conditional expression (27) is satisfied. 0.30 < m 12 / fw < 2.30 where, |m12| : an absolute value of the amount of change in distance from a lens surface closest to an image in the first lens group G1 to a lens surface closest to an object in the second lens group G2 on the optical axis during zooming from the wide angle end state to the telephoto end state, and fw : a focal length of the zoom optical system ZL in the wide angle end state.

[0122] The conditional expression (27) is a conditional expression for defining an adequate range for variable magnification burden of the second lens group G2. When the corresponding value of the conditional expression (27) exceeds the upper limit value, the amount of change (absolute value) in distance between the first lens group G1 and the second lens group G2 increases. Therefore, the variable magnification burden of the second lens group G2 increases, which makes it difficult to correct the coma aberration and the curvature of field. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (27) is preferably set to 1.90, and more preferably to 1.50.

[0123] When the corresponding value of the conditional expression (27) undergoes the lower limit value, the amount of change (absolute value) in distance between the first lens group G1 and the second lens group G2 is too small to secure a high zooming rate. In order to secure a zooming rate in a state in which the corresponding value of the conditional expression (27) undergoes the lower limit value, the power of the second lens group G2 needs to be stronger, which makes it difficult to correct the spherical aberration and the coma aberration. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (27) is preferably set to 0.50, and more preferably to 0.70.

[0124] Preferably, in the zoom optical system ZL according to the third configuration, the following group GR includes a fourth lens group G4 disposed closer to an image than the third lens group G3, and the following conditional expression (28) is satisfied. 0.050 < m 34 / fw < 0.800 where, |m34| : an absolute value of the amount of change in distance from a lens surface closest to an image in the third lens group G3 to a lens surface closest to an object in the fourth lens group G4 on the optical axis during zooming from the wide angle end state to the telephoto end state, and fw : a focal length of the zoom optical system ZL in the wide angle end state.

[0125] The conditional expression (28) is a conditional expression for achieving both the variable magnification burden and the aberration correction effect of the fourth lens group G4. When the corresponding value of the conditional expression (28) exceeds the upper limit value, the amount of change (absolute value) in distance between the third lens group G3 and the fourth lens group G4 increases. Therefore, the variable magnification burden of the fourth lens group G4 increases, which makes it difficult to correct spherical aberration in the telephoto end state and astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the upper limit value of the conditional expression (28) is preferably set to 0.650, and more preferably to 0.500.

[0126] When the lower limit value of the corresponding value of the conditional expression (28) undergoes the lower limit value, the amount of change (absolute value) in distance between the third lens group G3 and the fourth lens group G4 decreases, and thus the aberration correction effect of change in distance between the third lens group G3 and the fourth lens group G4 is less likely achieved. Therefore, achievement of both the aberration correction in the telephoto end state and the aberration correction in the wide angle end state is difficult, which makes it difficult to correct the spherical aberration and astigmatism in the wide angle end state. In order to ensure the effect of this configuration, the lower limit value of the conditional expression (28) is preferably set to 0.130, and more preferably to 0.180.

[0127] An optical apparatus according to the third configuration is configured with the zoom optical system having a configuration described above. As a specific example, a camera (optical apparatus) provided with the zoom optical system ZL according to the third configuration will be described with reference to FIG. 49. The camera 1 is a digital camera provided with the zoom optical system according to the configuration described above as an imaging lens 2 as illustrated in FIG. 49. In this camera 1, light from an object (subject) not illustrated is converged by the imaging lens 2, and reaches an image pickup device 3. Accordingly, light from the subject is imaged by the image pickup device 3, and is recorded in a memory, not illustrated, as a subject image. A photographer is allowed to photograph the subject by the camera 1 in this manner. It should be noted that the camera may be a mirror-less camera, or may be a single lens reflex type camera having a quick return mirror. In this configuration, by mounting the zoom optical system ZL according to the third configuration as the imaging lens, a small-sized optical apparatus including a small-sized vibration proof group is achieved.

[0128] Subsequently, an outline of a method for manufacturing the zoom optical system ZL according to the third configuration will be described with reference to FIG. 52. First, the first lens group G1 having a positive refractive power, the second lens group G2 closer to an image than the first lens group G1 and having a negative refractive power, the third lens group G3 closer to an image than the second lens group G2 and having a positive refractive power, and the following group GR consisting of at least one lens group closer to an image than the third lens group G3 are disposed in a lens barrel (Step ST21). Then, it is configured that 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 following group GR changes during zooming (Step ST22). Also, any one of the first lens group G1, the second lens group G2, the third lens group G3, and the following group GR includes a vibration proof group movable so as to have a displacement component in a direction perpendicular to an optical axis, the vibration proof group may consist of a positive lens, a first negative lens, and a second negative lens disposed in order from an object, and each lens is disposed within a lens barrel so that an air distance is present between the positive lens and the first negative lens and an air distance is present between the first negative lens and the second negative lens. (Step ST23). With such a manufacturing method, a telephoto type zoom optical system having a small-sized vibration proof group is manufactured.EXAMPLES

[0129] Hereinafter, the zoom optical system (telephoto type zoom lens) ZL according to examples in each configuration will be described with reference to the drawings. It should be noted that examples corresponding to the first configuration and the second configuration are Examples 1 to 11, and examples corresponding to the third configuration are Examples 9 to 12. FIG. 1, FIG. 5, FIG. 9, FIG. 13, FIG. 17, FIG. 21, FIG. 25, FIG. 29, FIG. 33, FIG. 37, FIG. 41, and FIG. 45 are cross-sectional views illustrating configurations and distributions of refractive power of the zoom optical system ZL {ZL (1) to ZL (12)} according to Examples 1 to 12. Each cross-sectional view illustrate positions of the respective lens groups when zooming from the wide angle end state (W) via the intermediate focal length state (M) to the telephoto end state (T) is performed. Arrows in the middle parts of these drawings indicate directions of movement of the first to fourth lens groups G1 to G4 (or the fifth lens group G5) when zooming (zooming operation) from the wide angle end state through the intermediate focal length state to the telephoto end state is performed. In addition, a direction of movement of the fourth lens group G4 for focusing from an infinity to a short distant object as a zooming group is indicated by an arrow associated with a term "FOCUSING". A direction of movement of at least part of the second lens group G2 for correcting an image blur as a vibration proof group is indicated by an arrow associated with a term "VIBRATION PROOF".

[0130] In these drawings (FIG. 1, FIG. 5, FIG. 9, FIG. 13, FIG. 17, FIG. 21, FIG. 25, FIG. 29, FIG. 33, FIG. 37, FIG. 41, and FIG. 45), each lens group is indicated by a combination of a sign G and a number, and each lens is indicated by a combination of a sign L and a number. In this case, in order to avoid complication by increases of type and number of the signs and the numbers, the lens groups are indicated by using combinations of the sign and the number independently from example to example. Therefore, even when the combination of the same sign and the number are used in examples, it does not mean that they have the same configuration.

[0131] Tables 1 to 12 are shown below. Among these tables, Table 1 shows data of Example 1, Table 2 shows data of Example 2, Table 3 shows data of Example 3, Table 4 shows data of Example 4, Table 5 shows data of Example 5, Table 6 shows data of Example 6, Table 7 shows data of Example 7, Table 8 shows data of Example 8, Table 9 shows data of Example 9, Table 10 shows data of Example 10, Table 11 shows data of Example 11, and Table 12 shows data of Example 12. In each example, a d-line (wavelength λ =587.6 nm) and a g-line (wavelength λ = 435.8 nm) are selected as objects of calculation of an aberration feature.

[0132] In tables of [General Data], f represents a focal length of a whole lens system, FNO represents F number, 2ω represents the angle of view (unit is degree (°) and ω is a half angle of view), and Y represents the maximum image height. TL represents a distance obtained by adding BF to a distance from a lens forefront surface to a lens last surface on an optical axis upon focusing on infinity, and BF indicates an air equivalent distance (back focus) from the lens last surface to an image surface I on the optical axis upon focusing on infinity. It should be noted that these values are indicated for the respective zooming states, that is, the wide angle end (W), the intermediate focal length (M) and the telephoto end (T). In the tables [General Data], ϕ represents a maximum effective diameter of a lens surface on the object side in a positive lens component of the third lens group disposed so as to oppose the image side of the aperture stop, Δ represents an absolute value of a difference between an aspherical amount at a position corresponding to the maximum effective diameter of the lens surface on the object side in the positive lens component and an aspherical amount at a position corresponding to the maximum effective diameter of the lens surface on the image side in the positive lens component.

[0133] In the table of [Lens Data], the surface numbers indicate the orders of the optical surfaces from the object side along the direction of the traveling of the rays, the sign R indicates a radius of curvature of each optical surface (a positive value is allocated to the surface where the center of curvature is located on the image side), and the sign D represents a distance to the next lens surface, which corresponds to the distance from each optical surface to the next optical surface (or an image surface) on the optical axis, the sign nd indicates the refractive index of a material of the optical member for d-line, and the sign vd indicates an abbe number with reference to the d-line of the material of the optical member. The sign "∞" of the radius of curvature indicates a flat surface or an opening, and (Aperture) S indicates an aperture stop S, respectively. Notation of the refractive index of air "nd= 1.00000" is omitted. When the lens surface is an aspherical surface, the surface number is asterisked, and a paraxial radius of curvature is shown in a column of the radius of curvature R.

[0134] In the tables of [Aspherical Data], the shapes of the aspherical surfaces listed in [Lens Data] are expressed by the following expression (a). In the following expression (a), X(y) represents a distance (sag amount) along the direction of the optical axis from a tangent surface at a vertex of the aspherical surface to a position on the aspherical surface at a height y, R represents a radius of curvature (paraxial radius of curvature) of a reference spherical surface, κ represents a conical coefficient, and Ai represents an i th< order aspherical coefficient. "E-n" represents "× 10 -n< ". For example, 1.234E - 05 = 1.234 × 10 -5< . It should be noted that the 2nd order aspherical coefficient A2 is 0, and notation of which is omitted.

[0135] In the tables of [Lens Group Data], starting surfaces (the surface closest to the object) and the focal lengths of the first to fourth lens groups G1 to G4 (or the fifth lens group G5) are shown.

[0136] In the tables of [Variable Distance Data], distances to the next lens surface of surface numbers which are indicated as "variable" in terms of distance to the next lens surface in the tables of [Lens Data]. Shown here are distances to the next lens surface in the respective zooming states, that is, in the wide angle end (W), the intermediate focal length (M), and the telephoto end (T) when in focus to infinity and short distance, respectively.

[0137] In the tables of [Conditional Expression Corresponding Value], values corresponding to the aforementioned conditional expressions (1) to (28) are shown.

[0138] In the following description, the unit "mm" is generally used for the focal length f, the radius of curvature R, the distance to the next lens surface D, and other lengths in all data values. However, the optical system is not limited thereto because the optical system achieves an equivalent optical performance even when the optical system is proportionally enlarged or proportionally contracted.

[0139] The description given thus far about the tables are common to all the examples, and the overlapped description will be omitted in the following description.(Example 1)

[0140] Example 1 will be described with reference to FIG. 1 to FIG. 4 and Table 1. FIG. 1 is a drawing illustrating a lens configuration of a zoom optical system according to Example 1. The zoom optical system ZL (1) according to Example 1 consists of, 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, an aperture stop S, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fourth lens groups G1 to G4 move in the directions indicated by the arrows shown in FIG. 1. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first configuration. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. Sign (+) or (-) accompanied with each lens group indicate the refractive power of each lens group, which applies to all other examples described below.

[0141] The first lens group G1 consists of, in order from an object, a meniscus shaped first positive lens L11 having a convex surface facing the object and a cemented lens consisting of a meniscus shaped negative lens L12 having a convex surface facing the object and a second positive lens L13 having a biconvex shape.

[0142] The second lens group G2 consists of, in order from an object, a meniscus shaped first negative lens L21 having a convex surface facing the object, a second negative lens L22 having a biconcave shape, and a cemented lens consisting of a third negative lens L23 having a biconcave shape and a positive lens L24 having a biconvex shape. In this example, the first negative lens L21 constitutes the negative subgroup, and the second negative lens L22, a third negative lens L23, and the positive lens L24 constitute the vibration proof group.

[0143] The third lens group G3 consists of, in order from an object, a first positive lens L31 having a flat-convex shape having a convex surface facing the object, a cemented lens consisting of a meniscus shaped negative lens L32 having a convex surface facing the object and a second positive lens L33 having a biconvex shape, and a third positive lens L34 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. A lens surface on the object side of the first positive lens L31 has an aspherical surface, and is disposed on the image side of the aperture stop S so as to face the aperture stop S. In this example, the first positive lens L31 constitutes the first object side subgroup, and the negative lens L32, the second positive lens L33, and the third positive lens L34 constitute the first image side subgroup. In the same manner, the first positive lens L31 constitutes the second object side subgroup, and the negative lens L32, the second positive lens L33, and the third positive lens L34 constitute the second image side subgroup.

[0144] The fourth lens group G4 consists of, in order from an object, a positive lens L41 meniscus shaped with a convex surface facing the image side, and a negative lens L42 having a biconcave shape disposed at an air distance from the positive lens L41. An image surface I is disposed on the image side of the fourth lens group G4.

[0145] In the zoom optical system ZL (1) according to Example 1, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (1) according to Example 1, the second negative lens L22 in the second lens group G2, the third negative lens L23, and the positive lens L24 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0146] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 1, the vibration proof coefficient is -1.16, the focal length is 51.50 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.29 mm. In the intermediate focal length state of Example 1, the vibration proof coefficient is -2.13, the focal length is 146.99 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.36 mm. In the telephoto end state of Example 1, the vibration proof coefficient is -3.07, the focal length is 242.50 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.41 mm.

[0147] In Table 1 shown below, data values of the zoom optical system according to Example 1 will be shown. (Table 1)[General Data]zooming rate 4.71ϕ 20.3200Δ 0.0952WMTf51.50146.99242.50FNO4.495.356.352ω32.011.06.8Y14.7514.7514.75TL137.496160.260176.460BF19.64242.68269.906 [Lens Data]

[0148] Surface NumberRDndvd162.659403.8561.5168063.92154.730190.150360.576622.0001.8919037.1435.510157.4251.4978282.65-265.34719D5(variable)6101.414931.5001.4978282.6742.789332.8808-95.811221.5001.7550052.3995.811222.60010-57.214531.5001.7725049.61145.103413.1961.8080922.712-332.69479D12 (variable)13∞1.000(Aperture S)14*25.994843.9731.5920167.015∞14.39216125.513961.5002.0006925.51723.079323.8721.4978282.618-67.486462.8341998.904022.6081.8019426.420-98.90402D20 (variable)21-66.565982.7651.8589522.722-32.479804.14323-26.599561.5001.7725049.624105.53899BF [Aspherical Data]Fourteenth Surface

[0149] κ = 1.00000 E + 00 A 4 = − 8.52477 E − 06 , A 6 = − 4.03131 E − 09 , A 8 = 1.30869 E − 11 , A 10 = − 1.23416 E − 13[Lens Group Data]

[0150] GroupStarting SurfaceFocal LengthG1195.53G26-29.71G31437.42G421-47.67 [Variable Distance Data]

[0151] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.50146.99242.50---Magnification----0.0548-0.1467-0.2554D0∞∞∞862.00839.18823.00D52.50030.82437.4282.50030.82437.428D1228.89410.8571.75028.89410.8571.750D2021.26710.7032.18224.71621.04816.950BF19.64242.68269.90616.19332.33755.138 [Conditional Expression Corresponding Value]

[0152] fGb / fGa = 1.6045 fVR / fGa = 1.2759 Dpn / - fGb = 0.0869 fa / fb = 0.4765 fα / fβ = 0.4765 fGc / − fGa = 1.2597 fGc / − fGb = 0.7851 mda / fw = 0.6782 mcb / fw = 0.3706 fp / fGp = 1.1733 LS / LGp = 0.5904 100 × Δ / φ = 0.4685 Dpn / − f 4 = 0.0869 fVR / f 2 = 1.2759 f 4 / f 2 = 1.6045 f 3 a / f 3 b = 0.4765 f 3 α / f 3 β = 0.4765 f 3 / − f 2 = 1.2597 f 3 / − f 4 = 0.7851 m 12 / fw = 0.6782 m 34 / fw = 0.3706

[0153] FIG. 2A, FIG. 2B and FIG. 2C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 1. FIG. 3A, FIG. 3B and FIG. 3C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 1. FIG. 4A, FIG. 4B, and FIG. 4C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 1.

[0154] In each aberration graph in FIG. 2A to FIG. 2C, FNO indicates an F number, and A indicates a half angle of view. It should be noted that the values of the F number corresponding to the maximum aperture are shown in the spherical aberration graphs, and the maximum values of the half angle of view are shown respectively in the astigmatism graphs and in the distortion graphs, and the values of the respective half angle of views are shown in the lateral aberration graphs. In each aberration graph in FIG. 3A to FIG. 3C, NA indicates a numerical aperture, and HO indicates the object height. It should be noted that the values of the numerical aperture corresponding to the maximum aperture are shown in the spherical aberration graphs, and the maximum values of the object height are shown respectively in the astigmatism graphs and in the distortion graphs, and the values of the respective object height are shown in the lateral aberration graphs. In each aberration graph in FIG. 4A to FIG. 4C, A indicates a half angle of view. It should be noted that, in the lateral aberration graph, the values of the half angle of view are shown. In each aberration graph, d indicates a d-line (wavelength λ =587.6 nm), and g indicates a g-line (wavelength λ =435.8 nm). In the astigmatism graphs, solid lines indicate a sagittal image surface, and broken lines indicate a meridional image surface, respectively. It should be noted that the same reference signs as this example are used in the following aberration graphs of the respective examples described below as well, and overlapped description will be omitted.

[0155] It is apparent from respective aberration graphs that the zoom optical system according to Example 1 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 2)

[0156] Example 2 will be described with reference to FIG. 5 to FIG. 8 and Table 2. FIG. 5 is a drawing illustrating a lens configuration of a zoom optical system according to Example 2. The zoom optical system ZL (2) according to Example 2 consists of, 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; an aperture stop S; a third lens group G3 having a positive refractive power; and a fourth lens group G4 having a negative refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fourth lens groups G1 to G4 move in the directions indicated by the arrows shown in FIG. 5. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first configuration. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. In Example 2, the first lens group G1, the second lens group G2 and the fourth lens group G4 have the same configuration as in Example 1, so that the same signs as those in Example 1 are allocated, and detailed descriptions of these lenses will be omitted.

[0157] The third lens group G3 consists of, in order from an object, a meniscus shaped first positive lens L31 having a convex surface facing the object, the second positive lens L32 meniscus shaped facing a convex surface thereof to the object side, a cemented lens consisting of a meniscus shaped negative lens L33 having a convex surface facing the object and a third lens L34 having a biconvex shape, and a fourth positive lens L35 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. A lens surface on the object side of the first positive lens L31 has an aspherical surface, and is disposed on the image side of the aperture stop S so as to face the aperture stop S. In this example, the first positive lens L31 and the second positive lens L32 constitute the first object side subgroup, and the negative lens L33, the third lens L34, and the fourth positive lens L35 constitute the first image side subgroup. In the same manner, the first positive lens L31 and the second positive lens L32 constitute the second object side subgroup, and the negative lens L33, the third lens L34, and the fourth positive lens L35 constitute the second image side subgroup.

[0158] In the zoom optical system ZL (2) according to Example 2, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (2) according to Example 2, the second negative lens L22 in the second lens group G2, the third negative lens L23, and the positive lens L24 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0159] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 2, the vibration proof coefficient is -1.21, the focal length is 51.50 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.28 mm. In the intermediate focal length state of Example 2, the vibration proof coefficient is -2.18, the focal length is 147.00 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.35 mm. In the telephoto end state of Example 2, the vibration proof coefficient is -3.12, the focal length is 242.51 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.41 mm.

[0160] In Table 2 shown below, data values of the zoom optical system according to Example 2 will be shown. (Table 2)[General Data]zooming rate 4.71ϕ 20.0640Δ 0.0763WMTf51.50147.00242.51FNO4.495.336.352ω32.011.06.8Y14.7514.7514.75TL135.610159.663176.402BF 19.52141.59968.637 [Lens Data]

[0161] Surface NumberRDndvd163.135844.0091.5168063.92169.418820.150358.782872.0001.9000436.3435.747227.2641. 4978282.65-369.04726D5 (variable)6129.611831.5001.4874970.3744.541955.2358-87.392541.5001.8212839.3972.630402.57210-48.979291.5001.7550052.31147.835683.3761.8080922.712-113.72334D12 (variable)13∞1.000(Aperture S)14*28.000003.1891.5920167.01583.028090.1501636.249633.1961.4928969.917264.5744112.16618232.658961.5002.0010029.11921.437723.9291.4978282.620-55.475982.1452175.790632.6131.8323831.622-129.42011D22 (variable)23-64.660822.8121.8080922.724-30.798873.51625-26.328631.5001.7612751.326100.00000BF [Aspherical Data]Fourteenth Surface

[0162] κ = 1.00000 E + 00 A 4 = − 7.36136 E − 06 , A 6 = − 2.03409 E − 09 , A 8 = 1.41855 E − 11 , A 10 = − 1.07528 E − 13[Lens Group Data]

[0163] GroupStarting SurfaceFocal LengthG1194.01G26-27.89G31435.97G423-47.07 [Variable Distance Data]

[0164] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.50147.00242.51---Magnification----0.0552-0.1470-0.2564D0∞∞∞857.82833.68816.97D52.00330.54436.9122.00330.54436.912D1226.0039.9061.75026.0039.9061.750D2221.26010.7912.28224.58421.18016.994BF19.52141.59968.63716.21231.31654.243 [Conditional Expression Corresponding Value]

[0165] fGb / fGa = 1.6877 fVR / fGa = 1.2947 Dpn / − fGb = 0.0747 fa / fb = 0.3462 fα / fβ = 0.3462 fGc / − fGa = 1.2896 fGc / − fGb = 0.7641 mda / fw = 0.6778 mcb / fw = 0.3685 fp / fGp = 1.9423 LS / LGp = 0.5006 100 × Δ / φ = 0.3803 Dpn / − f 4 = 0.0747 fVR / f 2 = 1.2947 f 4 / f 2 = 1.6877 f 3 a / f 3 b = 0.3462 f 3 α / f 3 β = 0.3462 f 3 / − f 2 = 1.2896 f 3 / − f 4 = 0.7641 m 12 / fw = 0.6778 m 34 / fw = 0.3685

[0166] FIG. 6A, FIG. 6B and FIG. 6C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 2. FIG. 7A, FIG. 7B and FIG. 7C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 2. FIG. 8A, FIG. 8B, and FIG. 8C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 2. It is apparent from respective aberration graphs that the zoom optical system according to Example 2 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 3)

[0167] Example 3 will be described with reference to FIG. 9 to FIG. 12 and Table 3. FIG. 9 is a drawing illustrating a lens configuration of a zoom optical system according to Example 3. The zoom optical system ZL (3) according to Example 3 consists of, 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, an aperture stop S, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fourth lens groups G1 to G4 move in the directions indicated by the arrows shown in FIG. 9. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first configuration. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. In Example 3, the first lens group G1, the second lens group G2 and the fourth lens group G4 have the same configuration as in Example 1, so that the same signs as those in Example 1 are allocated, and detailed descriptions of these lenses will be omitted.

[0168] The third lens group G3 consists of, in order from an object, a cemented lens consisting of a first positive lens L31 having a biconvex shape and a first negative lens L32 having a biconcave shape, a cemented lens consisting of a meniscus shaped second negative lens L33 having a convex surface facing the object, and a second positive lens L34 having a biconvex shape, and a third positive lens L35 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. A lens surface on the object side of the first positive lens L31 has an aspherical surface, and is disposed on the image side of the aperture stop S so as to face the aperture stop S. In this example, the first positive lens L31 and the first negative lens L32 constitute the first object side subgroup, and the second negative lens L33, the second positive lens L34, and the third positive lens L35 constitute the first image side subgroup. In the same manner, the first positive lens L31 and the first negative lens L32 constitute the second object side subgroup, and the second negative lens L33, the second positive lens L34, and the third positive lens L35 constitute the second image side subgroup.

[0169] In the zoom optical system ZL (3) according to Example 3, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (3) according to Example 3, the second negative lens L22 in the second lens group G2, the third negative lens L23, and the positive lens L24 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0170] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 3, the vibration proof coefficient is -1.14, the focal length is 51.49 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.30 mm. In the intermediate focal length state of Example 3, the vibration proof coefficient is -2.09, the focal length is 146.98 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.37 mm. In the telephoto end state of Example 3, the vibration proof coefficient is -3.01, the focal length is 242.46 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.42 mm.

[0171] In Table 3 shown below, data values of the zoom optical system according to Example 3 will be shown. (Table 3)[General Data]zooming rate 4.71ϕ 20.4220Δ 0.0884WMTf51.49146.98242.46FNO4.495.356.352ω32.011.06.8Y14.7514.7514.75TL137.501160.239176.433BF19.72143.12570.648 [Lens Data]

[0172] Surface NumberRDndvd162.507963.8771.5168063.92160.826000.150360.932702.0001.8919037.1435.470397.4291.4978282.65-263.78226D5(variable)6143.246911.5001. 4978282.6745.945332.6138-93.199851.5001.7550052.3998.936092.60010-59.003261.5001.7550052.31149.538293.0991.8080922.712-395.65819D12(variable)13∞1.000(Aperture S)14*26.400004.4351.6155764.215-108.157581.5001.6505533.0161060.5067014.39317131.843541.5002.0010029.11823.349473.8671.4978282.619-62.517330.4052073.982402.6331.7632029.521-140.65166D21 (variable)22-69.024332.7701.8589522.723-32.899414.16924-26.769441.5001.7725049.625105.64282BF [Aspherical Data]Fourteenth Surface

[0173] κ = 1.00000 E + 00 A 4 = − 7.74297 E − 06 , A 6 = − 3.79343 E − 09 , A 8 = 1.13866 E − 11 , A 10 = − 1.06621 E − 13[Lens Group Data]

[0174] GroupStarting SurfaceFocal LengthG1195.01G26-29.65G31437.08G422-48.44 [Variable Distance Data]

[0175] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.49146.98242.46---Magnification----0.0551-0.1485-0.2603D0∞∞∞856.43833.62817.43D52.62330.81637.3122.62330.81637.312D1229.11011. 0571.75029.11011.0571.750D2121.60810.8012.28425.14321.32517.367BF19.72143.12570.64816.20232.70855.893 [Conditional Expression Corresponding Value]

[0176] fGb / fGa = 1.6339 fVR / fGa = 1.3095 Dpn / − fGb = 0.0861 fa / fb = 0.4711 fα / fβ = 0.4711 fGc / − fGa = 1.2507 fGc / − fGb = 0.7655 mda / fw = 0.6737 mcb / fw = 0.3753 fp / fGp = 1.2010 LS / LGp = 0.5150 100 × Δ / φ = 0.4329 Dpn / − f 4 = 0.0861 fVR / f 2 = 1.3095 f 4 / f 2 = 1.6339 f 3 a / f 3 b = 0.4711 f 3 α / f 3 β = 0.4711 f 3 / − f 2 = 1.2507 f 3 / − f 4 = 0.7655 m 12 / fw = 0.6737 m 34 / fw = 0.3753

[0177] FIG. 10A, FIG. 10B and FIG. 10C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 3. FIG. 11A, FIG. 11B and FIG. 11C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 3. FIG. 12A, FIG. 12B, and FIG. 12C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 3. It is apparent from respective aberration graphs that the zoom optical system according to Example 3 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 4)

[0178] Example 4 will be described with reference to FIG. 13 to FIG. 16 and Table 4. FIG. 13 is a drawing illustrating a lens configuration of a zoom optical system according to Example 4. The zoom optical system ZL (4) according to Example 4 consists of, 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, an aperture stop S, a third lens group G3 having a positive refractive power, and a fourth lens group G4 having a negative refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fourth lens groups G1 to G4 move in the directions indicated by the arrows shown in FIG. 13. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first configuration. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. In Example 4, the first lens group G1 and the fourth lens group G4 have the same configuration as in the first configuration, so that the same reference signs as those in Example 1 are allocated, and detailed descriptions of these lenses will be omitted.

[0179] The second lens group G2 consists of, in order from an object, a meniscus shaped first negative lens L21 having a convex surface facing the object, the second negative lens L22 having a biconcave shape, and a meniscus shaped positive lens L23 having a convex surface facing the object. In this example, the first negative lens L21, the second negative lens L22, and the positive lens L23 (that is, all the lenses in the second lens group G2) constitute the vibration proof group.

[0180] The third lens group G3 consists of, in order from an object, a meniscus shaped first positive lens L31 having a convex surface facing the object, a cemented lens consisting of a meniscus shaped negative lens L32 having a convex surface facing the object and a second positive lens L33 having a biconvex shape, and a third positive lens L34 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. A lens surface on the object side of the first positive lens L31 has an aspherical surface, and is disposed on the image side of the aperture stop S so as to face the aperture stop S. In this example, the first positive lens L31 constitutes the first object side subgroup, and the negative lens L32, the second positive lens L33, and the third positive lens L34 constitute the first image side subgroup. In the same manner, the first positive lens L31 constitutes the second object side subgroup, and the negative lens L32, the second positive lens L33, and the third positive lens L34 constitute the second image side subgroup.

[0181] In the zoom optical system ZL (4) according to Example 4, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side. Also, in the zoom optical system ZL (4) according to Example 4, all the lenses in the second lens group G2 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0182] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 4, the vibration proof coefficient is -1.11, the focal length is 51.50 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.30 mm. In the intermediate focal length state of Example 4, the vibration proof coefficient is -2.06, the focal length is 146.99 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.37 mm. In the telephoto end state of Example 4, the vibration proof coefficient is -3.00, the focal length is 242.48 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.42 mm.

[0183] In Table 4 shown below, data values of the zoom optical system according to Example 4 will be shown. (Table 4)[General Data]zooming rate 4.71ϕ 21.2780Δ 0.0828WMTf51.50146.99242.48FNO4.495.196.352ω32.611.26.8Y14.7514.7514.75TL144.334161.305179.008BF20.07336.47965.178 [Lens Data]

[0184] Surface NumberRDndvd178.551252.8001.4874970.32111.144110.150363.923162.0001.9108235.2442.968167.3271.4978282.65-291.62059D5 (variable)61504.089301.5001.7147654.4766.057758-53.664952.065 1.5001.6180063.3940.892870.2771042.288952.9551.8080922.711141.93243D11(variable)12∞1.000(Aperture S)13*25.828731.6188163.914958.797029.65615116.290284.154 1.5002.0010029.11621.199324.1781.4978282.617-79.198407.5011886.661992.6491.7840826.519-168.51191D19(variable)20-79.676142.7491.8080922.721-33.680514.72122-26.627021.5001.8348142.723109.98588BF [Aspherical Data]Thirteenth Surface

[0185] κ = 1.00000 E + 00 A 4 = − 5.91135 E − 06 , A 6 = − 4.94128 E − 09 , A 8 = 1.13438 E − 11 , A 10 = − 9.44997 E − 14[Lens Group Data]

[0186] GroupStarting SurfaceFocal LengthG11121.71G26-41.86G31341.24G420-43.85 [Variable Distance Data]

[0187] W M T W M T InfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.50146.99242.48---Magnification----0.0557-0.1430-0.2573D0∞∞∞849.10832.12814.43D51.66840.69348.9331.66840.69348.933D1144.00612.5872.43244.00612.5872.432D1918.40511.3652.28321.53123.51817.138BF20.07336.47965.17816.96224.42550.643 [Conditional Expression Corresponding Value]

[0188] fGb / fGa = 1.0476 fVR / fGa = 1.0000 Dpn / − fGb = 0.1077 fa / fb = 0.2816 fα / fβ = 0.2816 fGc / − fGa = 0.9852 fGc / − fGb = 0.9404 mda / fw = 0.9178 mcb / fw = 0.3130 fp / fGp = 1.0384 LS / LGp = 0.5789 100 × Δ / φ = 0.3891 Dpn / − f 4 = 0.1077 fVR / f 2 = 1.0000 f 4 / f 2 = 1.0476 f 3 a / f 3 b = 0.2816 f 3 α / f 3 β = 0.2816 f 3 / − f 2 = 0.9852 f 3 / − f 4 = 0.9404 m 12 / fw = 0.9178 m 34 / fw = 0.3130

[0189] FIG. 14A, FIG. 14B and FIG. 14C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 4. FIG. 15A, FIG. 15B and FIG. 15C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 4. FIG. 16A, FIG. 16B, and FIG. 16C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 4. It is apparent from respective aberration graphs that the zoom optical system according to Example 4 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 5)

[0190] Example 5 will be described with reference to FIG. 17 to FIG. 20 and Table 5. FIG. 17 is a drawing illustrating a lens configuration of a zoom optical system according to Example 5. The zoom optical system ZL (5) according to Example 5 consists of, 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, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a negative refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fourth lens groups G1 to G4 move in the directions indicated by the arrows shown in FIG. 17, and the fifth lens group G5 is secured. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first configuration. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. The fifth lens group G5 corresponds to the image side lens group in the first configuration.

[0191] The first lens group G1 consists of, in order from an object, a meniscus shaped first positive lens L11 having a convex surface facing the object and a cemented lens consisting of a meniscus shaped negative lens L12 having a convex surface facing the object and a second positive lens L13 having a biconvex shape.

[0192] The second lens group G2 consists of, in order from an object, a meniscus shaped first negative lens L21 having a convex surface facing the object, a second negative lens L22 having a biconcave shape, and a cemented lens consisting of a third negative lens L23 having a biconcave shape and a positive lens L24 having a biconvex shape. In this example, the first negative lens L21 constitutes the negative subgroup, and the second negative lens L22, a third negative lens L23, and the positive lens L24 constitute the vibration proof group.

[0193] The third lens group G3 consists of, in order from an object, a first positive lens L31 having a biconvex shape, a cemented lens consisting of a negative lens L32 having a biconcave shape and a second positive lens L33 having a biconvex shape, and a third positive lens L34 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. A lens surface on the object side of the first positive lens L31 has an aspherical surface, and is disposed on the image side of the aperture stop S so as to face the aperture stop S. In this example, the first positive lens L31 constitutes the first object side subgroup, and the negative lens L32, the second positive lens L33, and the third positive lens L34 constitute the first image side subgroup. In the same manner, the first positive lens L31 constitutes the second object side subgroup, and the negative lens L32, the second positive lens L33, and the third positive lens L34 constitute the second image side subgroup.

[0194] The fourth lens group G4 consists of, in order from an object, a positive lens L41 meniscus shaped with a convex surface facing the image side, and a negative lens L42 having a biconcave shape disposed at an air distance from the positive lens L41.

[0195] The fifth lens group G5 consists of a negative lens L51 meniscus shaped with a convex surface facing the image side. An image surface I is disposed on the image side of the fifth lens group G5.

[0196] In the zoom optical system ZL (5) according to Example 5, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (5) according to Example 5, the second negative lens L22 in the second lens group G2, the third negative lens L23, and the positive lens L24 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0197] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 5, the vibration proof coefficient is -1.21, the focal length is 51.50 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.28 mm. In the intermediate focal length state of Example 5, the vibration proof coefficient is -2.14, the focal length is 146.99 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.36 mm. In the telephoto end state of Example 5, the vibration proof coefficient is -3.08, the focal length is 242.48 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.41 mm.

[0198] In Table 5 shown below, data values of the zoom optical system according to Example 5 will be shown. (Table 5)[General Data]zooming rate 4.71ϕ 18.5740Δ 0.0609WMTf51.50146.99242.48FNO4.495.226.352ω32.211.06.8Y14.7514.7514.75TL139.517159.237175.122BF 12.22812.16712.232 [Lens Data]

[0199] Surface NumberRDndvd159.186423.8661.6229958.12106.621570.150359.105742.0001.9027536.3436.522217.5781.4978282.65-659.38914D5 (variable)629.796531.5001.7291654.6725.166997.1808-88.479011.5001.8160046.6955.889991.66210-43.869101.5001.6516058.61168.867712.9851.8080922.712-109.96417D12 (variable) 13∞1.000(Aperture S)14*25.798383.8091.5920167.015-279.3735517.40616-247.496951.5002.0006925.51721.010703.3651.4978282.618-72.373032.8171951.646203.1671.7950428.720-54.87648D20 (variable)21-383.324683.9021.7353727.722-22.631650.33423-22.442281.5001.8160046.62452.43184D24 (variable)25-66.764651.5001.5168063.926-190.01529BF [Aspherical Data]Fourteenth Surface

[0200] κ = 1.00000 E + 00 A 4 = − 7.86750 E − 06 , A 6 = − 2.82414 E − 09 , A 8 = − 5.58002 E − 12 , A 10 = − 5.40323 E − 14[Lens Group Data]

[0201] GroupStarting SurfaceFocal LengthG11101.81G26-30.57G31437.64G421-47.69G525-200.00 [Variable Distance Data]

[0202] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.50146.99242.48---Magnification----0.0550-0.1399-0.2441D0∞∞∞854.43834.65818.83D51.20032.75739.1551.20032.75739.155D1229.6799.8451.51429.6799.8451.514D2020.21610.8551.38623.20621.66615.248D245.97323.39350.6132.98312.58136.751BF12.22812.16712.23212.24312.26212.521 [Conditional Expression Corresponding Value]

[0203] fGb / fGa = 1.5600 fVR / fGa = 1.1429 Dpn / − fGb = 0.0070 fa / fb = 0.5198 fα / fβ = 0.5198 fGc / − fGa = 1.2313 fGc / − fGb = 0.7893 mda / fw = 0.7370 mcb / fw = 0.3656 fp / fGp = 1.0647 LS / LGp = 0.6307 100 × Δ / φ = 0.3279 Dpn / − f 4 = 0.0070 fVR / f 2 = 1.1429 f 4 / f 2 = 1.5600 f 3 a / f 3 b = 0.5198 f 3 α / f 3 β = 0.5198 f 3 / − f 2 = 1.2313 f 3 / − f 4 = 0.7893 m 12 / fw = 0.7370 m 34 / fw = 0.3656

[0204] FIG. 18A, FIG. 18B and FIG. 18C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 5. FIG. 19A, FIG. 19B and FIG. 19C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 5. FIG. 20A, FIG. 20B, and FIG. 20C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 5. It is apparent from respective aberration graphs that the zoom optical system according to Example 5 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 6)

[0205] Example 6 will be described with reference to FIG. 21 to FIG. 24 and Table 6. FIG. 21 is a drawing illustrating a lens configuration of a zoom optical system according to Example 6. The zoom optical system ZL (6) according to Example 6 consists of, 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, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fourth lens groups G1 to G4 move in the directions indicated by the arrows shown in FIG. 21, and the fifth lens group G5 is secured. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first configuration. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. The fifth lens group G5 corresponds to the image side lens group in the first configuration.

[0206] The first lens group G1 consists of, in order from an object, a meniscus shaped first positive lens L11 having a convex surface facing the object and a cemented lens consisting of a meniscus shaped negative lens L12 having a convex surface facing the object and a second positive lens L13 having a biconvex shape.

[0207] The second lens group G2 consists of, in order from an object, a first negative lens L21 having a biconcave shape and a cemented lens consisting of a second negative lens L22 having a biconcave shape and a meniscus shaped positive lens L23 having a convex surface facing the object. In this example, the first negative lens L21, the second negative lens L22, and the positive lens L23 (that is, all the lenses in the second lens group G2) constitute the vibration proof group.

[0208] The third lens group G3 consists of, in order from an object, a first positive lens L31 having a biconvex shape, a cemented lens consisting of a meniscus shaped negative lens L32 having a convex surface facing the object and a second positive lens L33 having a biconvex shape, and a third positive lens L34 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. A lens surface on the object side of the first positive lens L31 has an aspherical surface, and is disposed on the image side of the aperture stop S so as to face the aperture stop S. In this example, the first positive lens L31 constitutes the first object side subgroup, and the negative lens L32, the second positive lens L33, and the third positive lens L34 constitute the first image side subgroup. In contrast, the first positive lens L31, the negative lens L32, and the second positive lens L33 constitute the second object side subgroup, and the third positive lens L34 constitute the second image side subgroup.

[0209] The fourth lens group G4 consists of, in order from an object, a positive lens L41 meniscus shaped with a convex surface facing the image side, and a negative lens L42 having a biconcave shape disposed at an air distance from the positive lens L41.

[0210] The fifth lens group G5 consists of a positive lens L51 meniscus shaped with a convex surface facing the image side. An image surface I is disposed on the image side of the fifth lens group G5.

[0211] In the zoom optical system ZL (6) according to Example 6, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (6) according to Example 6, all the lenses in the second lens group G2 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0212] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 6, the vibration proof coefficient is -1.18, the focal length is 51.50 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.29 mm. In the intermediate focal length state of Example 6, the vibration proof coefficient is -2.12, the focal length is 147.00 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.36 mm. In the telephoto end state of Example 6, the vibration proof coefficient is -3.02, the focal length is 242.50 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.42 mm.

[0213] In Table 6 shown below, data values of the zoom optical system according to Example 6 will be shown. (Table 6)[General Data]zooming rate 4.71ϕ 19.6040Δ 0.0756WMTf51.50147.00242.50FNO4.495.126.352ω33.011.26.8Y14.7514.7514.75TL149.546165.522181.571BF16.05716.03316.082 [Lens Data]

[0214] Surface NumberRDndvd173.232423.1361.4874970.32128.126370.150370.007682.0001.8919037.1444.095996.4841.4978282.65-346.69704D5 (variable)6-144.158591.5001.6180063.3769.263571.7428-59.868791.5001.6180063.3939.220002.8901.8080922.810116.35585D10 (variable)11∞1.000(Aperture S)12*22.820584.2701.5831359.413-352.542539.34514341.427581.5001.9537532.31517.615593.9481.4978282.616-89.901539.7381740.004243.3411.6200436.418-124.57218D18 (variable)19-48.944772.8491.6476933.720-25.840324.65121-21.325601.5001.6180063.32265.03472D22 (variable)23-102.083972.4431.4874970.324-69.00838BF [Aspherical Data]Twelfth Surface

[0215] κ = 1.00000 E + 00 A 4 = − 7.37913 E − 06 , A 6 = − 5.05231 E − 09 , A 8 = − 5.01437 E − 11 , A 10 = 1.59136 E − 13[Lens Group Data]

[0216] GroupStarting SurfaceFocal LengthG11122.71G26-38.09G31240.11G419-40.20G523426.58 [Variable Distance Data]

[0217] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.50147.00242.50---Magnification----0.0562-0.1393-0.2428D0∞∞∞844.43828.43812.43D56.64045.98455.0006.64045.98455.000D1042.95911.6612.49342.95911.6612.493D1814.01810.9212.59516.21122.31617.610D225.88516.93641.4143.6925.54226.399BF16.05716.03316.08216.07316.12716.367 [Conditional Expression Corresponding Value]

[0218] fGb / fGa = 1.0556 fVR / fGa = 1.0000 Dpn / − fGb = 0.1157 fa / fb = 0.2920 fα / fβ = 1.3131 fGc / − fGa = 1.0532 fGc / − fGb = 0.9978 mda / fw = 0.9390 mcb / fw = 0.2218 fp / fGp = 0.9202 LS / LGp = 0.5937 100 × Δ / φ = 0.3856 Dpn / − f 4 = 0.1157 fVR / f 2 = 1.0000 f 4 / f 2 = 1.0556 f 3 a / f 3 b = 0.2920 f 3 α / f 3 β = 1.3131 f 3 / − f 2 = 1.0532 f 3 / − f 4 = 0.9978 m 12 / fw = 0.9390 m 34 / fw = 0.2218

[0219] FIG. 22A, FIG. 22B and FIG. 22C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 6. FIG. 23A, FIG. 23B and FIG. 23C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 6. FIG. 24A, FIG. 24B, and FIG. 24C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 6. It is apparent from respective aberration graphs that the zoom optical system according to Example 6 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 7)

[0220] Example 7 will be described with reference to FIG. 25 to FIG. 28 and Table 7. FIG. 25 is a drawing illustrating a lens configuration of a zoom optical system according to Example 7. The zoom optical system ZL (7) according to Example 7 consists of, 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, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fourth lens groups G1 to G4 move in the directions indicated by the arrows shown in FIG. 25, and the fifth lens group G5 is secured. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first configuration. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. The fifth lens group G5 corresponds to the image side lens group in the first configuration.

[0221] The first lens group G1 consists of, in order from an object, a cemented lens consisting of a negative lens L11 meniscus shaped with a convex surface thereof facing the object side and a first positive lens L12 having a biconvex shape, and a meniscus shaped second positive lens L13 having a convex surface facing the object.

[0222] The second lens group G2 consists of, in order from an object, a first negative lens L21 having a biconcave shape and a cemented lens consisting of a second negative lens L22 having a biconcave shape and a meniscus shaped positive lens L23 having a convex surface facing the object. In this example, the first negative lens L21, the second negative lens L22, and the positive lens L23 (that is, all the lenses in the second lens group G2) constitute the vibration proof group.

[0223] The third lens group G3 consists of, in order from an object, a first positive lens L31 having a biconvex shape, a cemented lens consisting of a second positive lens L32 having a biconvex shape and a negative lens L33 having a biconcave shape, and a third positive lens L34 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. A lens surface on the object side of the first positive lens L31 has an aspherical surface, and is disposed on the image side of the aperture stop S so as to face the aperture stop S. In this example, the first positive lens L31 constitutes the first object side subgroup, and the second positive lens L32, the negative lens L33, and the third positive lens L34 constitute the first image side subgroup. In the same manner, the first positive lens L31 constitutes the second object side subgroup, and the second positive lens L32, the negative lens L33, and the third positive lens L34 constitute the second image side subgroup.

[0224] The fourth lens group G4 consists of, in order from an object, a positive lens L41 meniscus shaped with a convex surface facing the image side, and a negative lens L42 having a biconcave shape disposed at an air distance from the positive lens L41.

[0225] The fifth lens group G5 consists of a positive lens L51 meniscus shaped with a convex surface facing the image side. An image surface I is disposed on the image side of the fifth lens group G5.

[0226] In the zoom optical system ZL (7) according to Example 7, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (7) according to Example 7, all the lenses in the second lens group G2 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0227] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 7, the vibration proof coefficient is -1.04, the focal length is 51.50 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.33 mm. In the intermediate focal length state of Example 7, the vibration proof coefficient is -1.92, the focal length is 146.99 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.40 mm. In the telephoto end state of Example 7, the vibration proof coefficient is -2.87, the focal length is 242.46 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.44 mm.

[0228] In Table 7 shown below, data values of the zoom optical system according to Example 7 will be shown. (Table 7)[General Data]zooming rate 4.71ϕ 21.7420Δ 0.0812WMTf51.50146.99242.46FNO4.455.166.352ω32.611.06.8Y14.7514.7514.75TL159.487179.476189.442BF15.99815.98715.953 [Lens Data]

[0229] Surface NumberRDndvd1116.776662.0001.8919037.1266.264788.8041.4978282.63-157.077320.150456.719573.0511.4874970.3572.61791D5(variable)6-136.326921.5001.6180063.3790.783441.7458-67.460301.5001.6180063.3943.533142.9421.8466623.810121.70198D10 (variable)11∞1.000(Aperture S)12*21.277666.8761.5533271.713-187.463799.5661422.506664.4541.4978282.615-22.135211.5001.9537532.31621.567536.1781740.286515.4041.6989530.118-39.80095D18 (variable)19-31.696882.7811.6200436.420-20.942785.71921-17.596121.5001.6180063.322128.08217D22 (variable)23-151.043652.6911.4874970.324-69.67045BF [Aspherical Data]Twelfth Surface

[0230] κ = 1.00000 E + 00 A 4 = − 5.26085 E − 06 , A 6 = − 1.54081 E − 09 , A 8 = − 2.64260 E − 11 , A 10 = 0.00000 E + 00[Lens Group Data]

[0231] GroupStarting SurfaceFocal LengthG11145.38G26-44.06G31241.20G419-35.93G523262.44 [Variable Distance Data]

[0232] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.50146.99242.46---Magnification----0.0566-0.1414-0.2440D0∞∞∞834.43814.43804.43D57.43953.04760.8387.43953.04760.838D1052.75017.1772.57752.75017.1772.577D188.8107.2173.78010.78717.01818.785D225.12916.68636.9333.1516.88521.928BF 15.99815.98715.95316.01416.08416.242 [Conditional Expression Corresponding Value]

[0233] fGb / fGa = 0.8156 fVR / fGa = 1.0000 Dpn / − fGb = 0.1592 fa / fb = 0.1214 fα / fβ = 0.1214 fGc / − fGa = 0.9352 fGc / − fGb = 1.1466 mda / fw = 1.0369 mcb / fw = 0.0977 fp / fGp = 0.8481 LS / LGp = 0.4634 100 × Δ / φ = 0.3735 Dpn / − f 4 = 0.1592 fVR / f 2 = 1.0000 f 4 / f 2 = 0.8156 f 3 a / f 3 b = 0.1214 f 3 α / f 3 β = 0.1214 f 3 / − f 2 = 0.9352 f 3 / − f 4 = 1.1466 m 12 / fw = 1.0369 m 34 / fw = 0.0977

[0234] FIG. 26A, FIG. 26B and FIG. 26C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 7. FIG. 27A, FIG. 27B and FIG. 27C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 7. FIG. 28A, FIG. 28B, and FIG. 28C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 7. It is apparent from respective aberration graphs that the zoom optical system according to Example 7 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 8)

[0235] Example 8 will be described with reference to FIG. 29 to FIG. 32 and Table 8. FIG. 29 is a drawing illustrating a lens configuration of a zoom optical system according to Example 8. The zoom optical system ZL (8) according to Example 8 consists of, 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, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fourth lens groups G1 to G4 move in the directions indicated by the arrows shown in FIG. 29, and the fifth lens group G5 is secured. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first configuration. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. The fifth lens group G5 corresponds to the image side lens group in the first configuration.

[0236] The first lens group G1 consists of, in order from an object, a cemented lens consisting of a meniscus shaped negative lens L11 having a convex surface facing the object, and a first positive lens L12 having a biconvex shape.

[0237] The second lens group G2 consists of, in order from an object, a first negative lens L21 having a biconcave shape and a cemented lens consisting of a second negative lens L22 having a biconcave shape and a meniscus shaped positive lens L23 having a convex surface facing the object. In this example, the first negative lens L21, the second negative lens L22, and the positive lens L23 (that is, all the lenses in the second lens group G2) constitute the vibration proof group.

[0238] The third lens group G3 consists of, in order from an object, a first positive lens L31 having a biconvex shape, a cemented lens consisting of a negative lens L32 having a biconcave shape and a second positive lens L33 having a biconvex shape, and a third positive lens L34 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. A lens surface on the object side of the first positive lens L31 has an aspherical surface, and is disposed on the image side of the aperture stop S so as to face the aperture stop S. In this example, the first positive lens L31 constitutes the first object side subgroup, and the negative lens L32, the second positive lens L33, and the third positive lens L34 constitute the first image side subgroup. In the same manner, the first positive lens L31 constitutes the second object side subgroup, and the negative lens L32, the second positive lens L33, and the third positive lens L34 constitute the second image side subgroup.

[0239] The fourth lens group G4 consists of, in order from an object, a positive lens L41 meniscus shaped with a convex surface facing the image side, and a negative lens L42 having a biconcave shape disposed at an air distance from the positive lens L41.

[0240] The fifth lens group G5 consists of a positive lens L51 meniscus shaped with a convex surface facing the image side. An image surface I is disposed on the image side of the fifth lens group G5.

[0241] In the zoom optical system ZL (8) according to Example 8, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (8) according to Example 8, all the lenses in the second lens group G2 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0242] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 8, the vibration proof coefficient is -1.02, the focal length is 51.50 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.33 mm. In the intermediate focal length state of Example 8, the vibration proof coefficient is -1.86, the focal length is 147.00 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.41 mm. In the telephoto end state of Example 8, the vibration proof coefficient is -2.68, the focal length is 242.50 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.47 mm.

[0243] In Table 8 shown below, data values of the zoom optical system according to Example 8 will be shown. (Table 8)[General Data]zooming rate 4.71ϕ 20.8580Δ 0.0803WMTf51.50147.00242.50FNO4.495.236.352ω33.011.26.8Y14.7514.7514.75TL156.512177.844189.541BF15.98716.00516.052 [Lens Data]

[0244] Surface NumberRDndvd166.205792.0001.8919037.1246.514669.9651.4978282.63-253.04363D3 (variable)4-113.599111.5001.6180063.3596.538481.5436-75.733541.5001.5891361.2742.438452.8911.8466623.88109.64148D8 (variable)9∞1.000(Aperture S)10*23.813914.5941.6188163.911-192.3566111.07412-109.321601.5001.9537532.31318.859593.9911.4978282.614-49.1178610.4821542.163493.1311.6989530.116-192.85659D16 (variable)17-58.009103.1011.6200436.418-24.005283.39919-20.052191.5001.6180063.32056.15912D20 (variable)21-99.073273.2311.4874970.322-69.36557BF [Aspherical Data]Tenth Surface

[0245] κ = 1.00000 E + 00 A 4 = − 6.04393 E − 06 , A 6 = − 5.13093 E − 09 , A 8 = − 1.58013 E − 11 , E 10 = 0.00000 E + 00[Lens Group Data]

[0246] GroupStarting SurfaceFocal LengthG11143.01G24-46.04G31043.15G417-40.12G521458.20 [Variable Distance Data]

[0247] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.50147.00242.50---Magnification----0.0568-0.1420-0.2429D0∞∞∞837.39816.08804.43D33.18950.97161.3683.18950.97161.368D852.75016.9642.61352.75016.9642.613D1612.2208.6542.56114.35218.72117.566D205.96418.84840.5453.8338.78125.540BF15.98716.00516.05216.00316.10316.338 [Conditional Expression Corresponding Value]

[0248] fGb / fGa = 0.8714 fVR / fGa = 1.0000 Dpn / − fGb = 0.0847 fa / fb = 0.1658 fα / fβ = 0.1658 fGc / − fGa = 0.9373 fGc / − fGb = 1.0757 mda / fw = 1.1297 mcb / fw = 0.1876 fp / fGp = 0.8001 LS / LGp = 0.6199 100 × Δ / φ = 0.3850 Dpn / − f 4 = 0.0847 fVR / f 2 = 1.0000 f 4 / f 2 = 0.8714 f 3 a / f 3 b = 0.1658 f 3 α / f 3 β = 0.1658 f 3 / − f 2 = 0.9373 f 3 / − f 4 = 1.0757 m 12 / fw = 1.1.1297 m 34 / fw = 0.1876

[0249] FIG. 30A, FIG. 30B and FIG. 30C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 8. FIG. 31A, FIG. 31B and FIG. 31C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 8. FIG. 32A, FIG. 32B, and FIG. 32C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 8. It is apparent from respective aberration graphs that the zoom optical system according to Example 8 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 9)

[0250] Example 9 will be described with reference to FIG. 33 to FIG. 36 and Table 9. FIG. 33 is a drawing illustrating a lens configuration of a zoom optical system according to Example 9. The zoom optical system ZL (9) according to Example 9 consists of, 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; an aperture stop S; a third lens group G3 having a positive refractive power; a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a negative refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fifth lens groups G1 to G5 move in the directions indicated by the arrows shown in FIG. 33. Also, for zooming from the wide angle end state (W) to the telephoto end state (T), the third lens group G3 and the fifth lens group G5 move synchronously. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first embodiment. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. The fifth lens group G5 corresponds to the image side lens group in the first configuration. Also, the fourth lens group G4 and the fifth lens group G5 constitute the following group GR in the third configuration.

[0251] The first lens group G1 consists of, in order from an object, a first positive lens L11 having a biconvex shape, and a cemented lens consisting of a meniscus shaped negative lens L12 having a convex surface facing the object and a meniscus shaped second positive lens L13 having a convex surface facing the object.

[0252] The second lens group G2 consists of, in order from an object, a positive lens L21 having a biconvex shape, first negative lens L22 having a biconcave shape disposed at an air distance from the positive lens L21, and a second negative lens L23 having a biconcave shape disposed at an air distance from the first negative lens L22. In this example, the positive lens L21, the first negative lens L22, and the second negative lens L23 (that is, all the lenses in the second lens group G2) constitute the vibration proof group.

[0253] The third lens group G3 consists of, in order from an object, a cemented lens consisting of a first positive lens L31 having a biconvex shape and a first negative lens L32 meniscus shaped with a convex surface facing the image side, a meniscus shaped second positive lens L33 having a convex surface facing the object, a cemented lens consisting of a meniscus shaped second negative lens L34 having a convex surface facing the object and a third positive lens L35 having a biconvex shape, and a fourth positive lens L36 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. In this example, the first positive lens L31, the first negative lens L32, and the second positive lens L33 constitute the first object side subgroup, and the second negative lens L34, the third positive lens L35, and the fourth positive lens L36 constitute the first image side subgroup. In the same manner, the first positive lens L31, the first negative lens L32, and the second positive lens L33 constitute the second object side subgroup, and the second negative lens L34, the third positive lens L35, and the fourth positive lens L36 constitute the second image side subgroup.

[0254] The fourth lens group G4 consists of, in order from an object, a positive lens L41 meniscus shaped with a convex surface facing the image side, and a negative lens L42 having a biconcave shape disposed at an air distance from the positive lens L41.

[0255] The fifth lens group G5 consists of, in order from an object, a negative lens L51 meniscus shaped with a convex surface facing the image side, and a positive lens L52 meniscus shaped with a convex surface facing the image side. An image surface I is disposed on the image side of the fifth lens group G5.

[0256] In the zoom optical system ZL (9) according to Example 9, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (9) according to Example 9, all the lenses in the second lens group G2 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0257] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 9, the vibration proof coefficient is -1.14, the focal length is 51.25 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.29 mm. In the intermediate focal length state of Example 9, the vibration proof coefficient is -2.14, the focal length is 150.00 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.37 mm. In the telephoto end state of Example 9, the vibration proof coefficient is -3.00, the focal length is 243.75 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.42 mm.

[0258] In Table 9 shown below, data values of the zoom optical system according to Example 9 will be shown. (Table 9)[General Data]zooming rate 4.76ϕ 19.3516Δ 0.0000WMTf51.25150.00243.75FNO4.605.726.402ω30.810.46.4Y14.0014.0014.00TL130.819173.736184.319BF14.31934.52450.036 [Lens Data]

[0259] Surface NumberRDndvd11416.791202.9891.5891361.22-147.917840.000361.002492.0001.6727032.2438.222604.8591.5168063.95119.14290D5 (variable)6102.369772.9021.8466623.87-68.949320.0008-390.038511.0001.8348142.7950.577122.26110-32.769891.0001.8348142.711327.50948D11(variable)12∞1.500(Aperture S)1363.227684.2901.6180063.314-25.883971.0001.8502632.415-67.958130.0001623.410922.7011.8348142.71739.307379.905185597.303001.0001.8348142.71916.128403.9161.4978282.620-55.018110.0002193.691512.0311.8502632.422-181.95197D22(variable)23-55.965432.2641.7173629.624-23.938911.32525-26.150671.0001.8348142.726157.23705D26(variable)27-17.838041.0001.4978282.628-36.299430.00029-389.263372.5601.8500027.030-56.49544BF [Lens Group Data]

[0260] GroupStarting SurfaceFocal LengthG11136.65G26-39.80G31334.62G423-51. 61G527-1999.99 [Variable Distance Data]

[0261] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.25150.00243.75---Magnification----0.0554-0.1564-0.2667D0∞∞∞869.18826.26815.68D52.00045.57756.2632.00045.57756.263D1138.11317.2471.63338.11317.2471.633D2216.6566.5482.58419.13714.28817.571D268.22718.33622.3005.74710.5967.313BF14.31934.52450.03614.31934.52450.036 [Conditional Expression Corresponding Value]

[0262] fGb / fGa = 1.2967 fVR / fGa = 1.0000 Dpn / − fGb = 0.0257 fa / fb = 0.1146 fα / fβ = 0.1146 fGc / − fGa = 0.8698 fGc / − fGb = 0.6708 mda / fw = 1.0588 mcb / fw = 0.2746 Dpn / − f 4 = 0.0257 fVR / f 2 = 1.0000 f 4 / f 2 = 1.2967 f 3 a / f 3 b = 0.1146 f 3 α / f 3 β = 0.1146 f 3 / − f 2 = 0.8698 f 3 / − f 4 = 0.6708 m 12 / fw = 1.0588 m 34 / fw = 0.2746 f 4 / − f 2 = 1.2967 f 3 a / f 3 b = 0.1146 f 3 α / f 3 β = 0.1146 f 3 / − f 2 = 0.8698 f 3 / f 4 = 0.6708 m 12 / fw = 1.0588 m 34 / fw = 0.2746

[0263] FIG. 34A, FIG. 34B and FIG. 34C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 9. FIG. 35A, FIG. 35B and FIG. 35C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 9. FIG. 36A, FIG. 36B, and FIG. 36C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 9. It is apparent from respective aberration graphs that the zoom optical system according to Example 9 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 10)

[0264] Example 10 will be described with reference to FIG. 37 to FIG. 40 and Table 10. FIG. 37 is a drawing illustrating a lens configuration of a zoom optical system according to Example 10. The zoom optical system ZL (10) according to Example 10 consists of, 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, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a negative refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fifth lens groups G1 to G5 move in the directions indicated by the arrows shown in FIG. 37. Also, for zooming from the wide angle end state (W) to the telephoto end state (T), the third lens group G3 and the fifth lens group G5 move synchronously. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first configuration. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. The fifth lens group G5 corresponds to the image side lens group in the first configuration. Also, the fourth lens group G4 and the fifth lens group G5 constitute the following group GR in the third configuration.

[0265] The first lens group G1 consists of, in order from an object, a cemented lens consisting of a meniscus shaped negative lens L11 having a convex surface facing the object and the meniscus shaped first positive lens L12 having a convex surface facing the object, and a second positive lens L13 having a biconvex shape.

[0266] The second lens group G2 consists of, in order from an object, a positive lens L21 having a biconvex shape, first negative lens L22 having a biconcave shape disposed at an air distance from the positive lens L21, and a second negative lens L23 having a flat-concave shape with a concave surface facing the object side and disposed at an air distance from the first negative lens L22. In this example, the positive lens L21, the first negative lens L22, and the second negative lens L23 (that is, all the lenses in the second lens group G2) constitute the vibration proof group.

[0267] The third lens group G3 consists of, in order from an object, a cemented lens consisting of a first positive lens L31 having a biconvex shape and a first negative lens L32 meniscus shaped with a convex surface facing the image side, a meniscus shaped second positive lens L33 having a convex surface facing the object, a cemented lens consisting of a meniscus shaped second negative lens L34 having a convex surface facing the object and a third positive lens L35 having a biconvex shape, and a fourth positive lens L36 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. In this example, the first positive lens L31, the first negative lens L32, and the second positive lens L33 constitute the first object side subgroup, and the second negative lens L34, the third positive lens L35, and the fourth positive lens L36 constitute the first image side subgroup. In the same manner, the first positive lens L31, the first negative lens L32, and the second positive lens L33 constitute the second object side subgroup, and the second negative lens L34, the third positive lens L35, and the fourth positive lens L36 constitute the second image side subgroup.

[0268] The fourth lens group G4 consists of, in order from an object, a positive lens L41 having a biconvex shape, and a negative lens L42 having a biconcave shape disposed at an air distance from the positive lens L41.

[0269] The fifth lens group G5 consists of, in order from an object, a negative lens L51 meniscus shaped with a convex surface facing the image side, and a positive lens L52 having a biconvex shape. An image surface I is disposed on the image side of the fifth lens group G5.

[0270] In the zoom optical system ZL (10) according to Example 10, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (10) according to Example 10, all the lenses in the second lens group G2 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0271] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 10, the vibration proof coefficient is -1.15, the focal length is 51.25 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.29 mm. In the intermediate focal length state of Example 10, the vibration proof coefficient is -2.17, the focal length is 150.00 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.36 mm. In the telephoto end state of Example 10, the vibration proof coefficient is -3.00, the focal length is 243.75 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.42 mm.

[0272] In Table 10 shown below, data values of the zoom optical system according to Example 10 will be shown. (Table 10)[General Data]zooming rate 4.76ϕ 19.1495Δ 0.0000WMTf51.25150.00243.75FNO4.605.446.402ω32.411.06.8Y14.7514.7514.75TL130.819167.081182.443BF14.31930.46445.827 [Lens Data]

[0273] Surface NumberRDndvd1146.125882.0001.6727032.2254.866604.4281.5168063.93312.177750.0004101.162523.9521.5891361.25-323.20365D5 (variable)643.383473.0581.8466623.87-138.792210.6878-376.509431.0001.8061041.0928.984422.79110-34.246021.0001.8061041.011∞D11 (variable)12∞1.500(Aperture S)1391.933964.5971.6180063.314-20.706901.0001.8502632.415-85.248750.0001626.524972.7661.8348142.71753.588879.298181031.023201.0001.8348142.71919.274654.3381.4978282.620-49.993160.0002171.993042.4121.7950428.722-115.55384D22 (variable)23169183.090002.2961.7282528.424-37.984460.52725-42.619551.0001.8348142.72661.50123D26 (variable)27-19.991851.0001.8348142.728-44.543250.00029106.576842.3151.8466623.830-279.81339BF [Lens Group Data]

[0274] GroupStarting SurfaceFocal LengthG11130.24G26-40.13G31334.55G423-73.25G527-88.38 [Variable Distance Data]

[0275] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.25150.00243.75---Magnification----0.0550-0.1542-0.2580D0∞∞∞869.21832.89817.52D51.50042.94753.9641.50042.94753.964D1133.84712.5181.50033.84712.5181.500D2220.2459.0192.00023.64118.76516.987D267.94419.17026.1894.5489.42311.201BF14.31930.46445.82714.31930.46445.827 [Conditional Expression Corresponding Value]

[0276] fGb / fGa = 1.8255 fVR / fGa = 1.0000 Dpn / − fGb = 0.0072 fa / fb = 0.5679 fα / fβ = 0.5679 fGc / − fGa = 0.8610 fGc / − fGb = 0.4716 mda / fw = 1.0237 mcb / fw = 0.3560 Dpn / − f 4 = 0.0072 fVR / f 2 = 1.0000 f 4 / f 2 = 1.8255 f 3 a / f 3 b = 0.5679 f 3 α / f 3 β = 0.5679 f 3 / − f 2 = 0.8610 f 3 / − f 4 = 0.4716 m 12 / fw = 1.0237 m 34 / fw = 0.3560 f 4 / − f 2 = 1.8255 f 3 a / f 3 b = 0.5679 f 3 α / f 3 β = 0.5679 f 3 / − f 2 = 0.8610 f 3 / f 4 = 0.4716 m 12 / fw = 1.0237 m 34 / fw = 0.3560

[0277] FIG. 38A, FIG. 38B and FIG. 38C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 10. FIG. 39A, FIG. 39B and FIG. 39C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 10. FIG. 40A, FIG. 40B, and FIG. 40C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 10. It is apparent from respective aberration graphs that the zoom optical system according to Example 10 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 11)

[0278] Example 11 will be described with reference to FIG. 41 to FIG. 44 and Table 11. FIG. 41 is a drawing illustrating a lens configuration of a zoom optical system according to Example 11. The zoom optical system ZL (11) according to Example 11 consists of, 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, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a negative refractive power, and a fifth lens group G5 having a positive refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fifth lens groups G1 to G5 move in the directions indicated by the arrows shown in FIG. 41. Also, for zooming from the wide angle end state (W) to the telephoto end state (T), the third lens group G3 and the fifth lens group G5 move synchronously. The first lens group G1 corresponds to the object side lens group in the first configuration. The second lens group G2 corresponds to the first negative lens group in the first configuration. The third lens group G3 corresponds to the intermediate lens group in the first configuration. The fourth lens group G4 corresponds to the second negative lens group in the first configuration. The fifth lens group G5 corresponds to the image side lens group in the first configuration. Also, the fourth lens group G4 and the fifth lens group G5 constitute the following group GR in the third configuration.

[0279] The first lens group G1 consists of, in order from an object, a first positive lens L11 having a biconvex shape, and a cemented lens consisting of a meniscus shaped negative lens L12 having a convex surface facing the object and a meniscus shaped second positive lens L13 having a convex surface facing the object.

[0280] The second lens group G2 consists of, in order from an object, a positive lens L21 having a biconvex shape, first negative lens L22 having a biconcave shape disposed at an air distance from the positive lens L21, and a second negative lens L23 having a biconcave shape disposed at an air distance from the first negative lens L22. In this example, the positive lens L21, the first negative lens L22, and the second negative lens L23 (that is, all the lenses in the second lens group G2) constitute the vibration proof group.

[0281] The third lens group G3 consists of, in order from an object, a cemented lens consisting of a meniscus shaped first negative lens L31 having a convex surface facing the object and a first positive lens L32 having a biconvex shape, a meniscus shaped second positive lens L33 having a convex surface facing the object, a cemented lens consisting of a second negative lens L34 having a biconcave shape and a third positive lens L35 having a biconvex shape, and a fourth positive lens L36 having a biconvex shape. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming.

[0282] The fourth lens group G4 consists of, in order from an object, a positive lens L41 meniscus shaped with a convex surface facing the image side, and a negative lens L42 having a biconcave shape disposed at an air distance from the positive lens L41.

[0283] The fifth lens group G5 consists of, in order from an object, a negative lens L51 meniscus shaped with a convex surface facing the image side, and a positive lens L52 having a biconvex shape. An image surface I is disposed on the image side of the fifth lens group G5.

[0284] In the zoom optical system ZL (11) according to Example 11, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (11) according to Example 11, all the lenses in the second lens group G2 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0285] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 11, the vibration proof coefficient is -1.13, the focal length is 51.25 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.30 mm. In the intermediate focal length state of Example 11, the vibration proof coefficient is -2.10, the focal length is 150.00 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.37 mm. In the telephoto end state of Example 11, the vibration proof coefficient is -3.00, the focal length is 243.75 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.42 mm.

[0286] In Table 11 shown below, data values of the zoom optical system according to Example 11 will be shown. (Table 11)[General Data]zooming rate 4.76ϕ 19.8572Δ 0.0000WMTf51.25150.00243.75FNO4.605.776.402ω30.610.46.4Y14.0014.0014.00TL130.819175.365184.319BF14.31933.78449.264 [Lens Data]

[0287] Surface NumberRDndvd11032.247402.9691.5891361.22-156.177600.000364.618122.0001.6727032.2440.084764.7041.5168063.95125.32467D5 (variable)690.271582.9111.8466623.87-75.178920.0008-499.828521.0001.8348142.7947.060422.35010-33.142761.0001.8348142.711486.54218D11(variable)12∞1.500(Aperture S)1352.692811.0001. 8502632.41421.654004.5861.4978282.615-93.232740.0001621.059513.4101.8348142.71763.8340010.26318-535.107461.0001.8348142.71913.461174.0501.5182358.820-111.146810.00021144.456042.1211.8348142.722-79.68661D22(variable)23-148.472502.5541.6476933.724-24.785901.39325-25.526431.0001.8348142.72672.13865D26 (variable)27-18.416731.0001.4978282.628-37.675110.00029947.699092.5941.8500027.03066.87297BF [Lens Group Data]

[0288] GroupStarting SurfaceFocal LengthG11142.56G26-40.62G31334.44G423-46.86G5272000.01 [Variable Distance Data]

[0289] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.25150.00243.75---Magnification----0.0553-0.1558-0.2664D0∞∞∞869.18824.63815.68D52.00048.02357.8522.00048.02357.852D1138.89017.9491.59338.89017.9491.593D2213.9584.8152.22216.31812.35917.209D268.24717.38919.9825.8869.8454.996BF14.31933.78449.26414.31933.78449.264 [Conditional Expression Corresponding Value]

[0290] fGb / fGa = 1.1538 fVR / fGa = 1.0000 Dpn / − fGb = 0.0297 fGc / − fGa = 0.8480 fGc / − fGb = 0.7350 mda / fw = 1.0898 mcb / fw = 0.2290 Dpn / − f 4 = 0.0297 fVR / f 2 = 1.0000 f 4 / f 2 = 1.1538 f 3 / − f 2 = 0.8480 f 3 / − f 4 = 0.7350 m 12 / fw = 1.0898 m 34 / fw = 0.2290 f 4 / − f 2 = 1.1538 f 3 / − f 2 = 0.8480 f 3 / f 4 = 0.7350 m 12 / fw = 1.0898 m 34 / fw = 0.2290

[0291] FIG. 42A, FIG. 42B and FIG. 42C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 11. FIG. 43A, FIG. 43B and FIG. 43C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 11. FIG. 44A, FIG. 44B, and FIG. 44C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 11. It is apparent from respective aberration graphs that the zoom optical system according to Example 11 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.(Example 12)

[0292] Example 12 will be described with reference to FIG. 45 to FIG. 48 and Table 12. FIG. 45 is a drawing illustrating a lens configuration of a zoom optical system according to Example 12. The zoom optical system ZL (12) according to Example 12 consists of, 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, an aperture stop S, a third lens group G3 having a positive refractive power, a fourth lens group G4 having a positive refractive power, and a fifth lens group G5 having a negative refractive power. For zooming from the wide angle end state (W) to the telephoto end state (T), the first to fifth lens groups G1 to G5 move in the directions indicated by the arrows shown in FIG. 45. Also, for zooming from the wide angle end state (W) to the telephoto end state (T), the third lens group G3 and the fifth lens group G5 move synchronously. The fourth lens group G4 and the fifth lens group G5 constitute the following group GR in the third configuration.

[0293] The first lens group G1 consists of, in order from an object, a first positive lens L11 having a biconvex shape, and a cemented lens consisting of a meniscus shaped negative lens L12 having a convex surface facing the object and a second positive lens L13 having a biconvex shape.

[0294] The second lens group G2 consists of, in order from an object, a positive lens L21 having a biconvex shape, first negative lens L22 having a biconcave shape disposed at an air distance from the positive lens L21, and a second negative lens L23 having a biconcave shape disposed at an air distance from the first negative lens L22. In this example, the positive lens L21, the first negative lens L22, and the second negative lens L23 (that is, all the lenses in the second lens group G2) constitute the vibration proof group.

[0295] The third lens group G3 consists of, in order from an object, a first positive lens L31 having a biconvex shape, a cemented lens consisting of a second positive lens L32 having a biconvex shape and a negative lens L33 having a biconcave shape, and a third positive lens L34 meniscus shaped with a convex surface facing the image side. The aperture stop S is provided near the object side of the third lens group G3, and moves integrally with the third lens group G3 during zooming. In this example, the first positive lens L31 constitutes the first object side subgroup, and the second positive lens L32, the negative lens L33, and the third positive lens L34 constitute the first image side subgroup. In contrast, the first positive lens L31, the second positive lens L32, and the negative lens L33 constitute the second object side subgroup, and the third positive lens L34 constitute the second image side subgroup.

[0296] The fourth lens group G4 consists of, in order from an object, a cemented lens consisting of a positive lens L41 having a biconvex shape and a negative lens L42 meniscus shaped with a convex surface facing the image side.

[0297] The fifth lens group G5 consists of, in order from an object, a cemented lens consisting of a positive lens L51 meniscus shaped with a convex surface facing the image side and a negative lens L52 having a biconcave shape. An image surface I is disposed on the image side of the fifth lens group G5.

[0298] In the zoom optical system ZL (12) according to Example 12, focusing from the infinity to the short distant object is achieved by moving all the lenses in the fourth lens group G4 to the image side along the optical axis. Also, in the zoom optical system ZL (12) according to Example 12, all the lenses in the second lens group G2 constitute the vibration proof group movable in the direction perpendicular to the optical axis, and corrects a displacement of an imaging position due to camera shake or the like (image blur on the image surface I).

[0299] It should be noted that, in order to correct a rotational blur at an angle θ with a lens having, in the whole system, a focal length f and a vibration proof coefficient (ratio of the amount of movement of the image on the imaging surface with respect to the amount of movement of the moving lens group in the shake compensation) K, the moving lens group for shake compensation may simply move in a direction perpendicular to the optical axis by (f·tan θ) / K. In the wide angle end state of Example 12, the vibration proof coefficient is -1.04, the focal length is 51.25 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.38° is -0.32 mm. In the intermediate focal length state of Example 12, the vibration proof coefficient is -2.19, the focal length is 150.00 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.36 mm. In the telephoto end state of Example 12, the vibration proof coefficient is -3.00, the focal length is 243.75 mm. Therefore, the amount of movement of the vibration-proof lens group for correcting the rotational blur of 0.30° is -0.42 mm.

[0300] In Table 12 shown below, data values of the zoom optical system according to Example 12 will be shown. (Table 12)[General Data]zooming rate 4.76ϕ 21.3468Δ 0.0000WMTf51.25150.00243.75FNO4.605.756.402ω32.611.06.8Y14.7514.7514.75TL130.719161.801185.719BF14.63935.31250.247 [Lens Data]

[0301] Surface NumberRDndvd1108.214393.4731.5891361.22-1179.140600.1003222.263012.0001.6727032.2460.360654.6871.5168063.95-909.25899D5 (variable)653.206763.3381.8466623.87-102.104780.1008-204.742511.0001.8350043.0938.402972.77710-37.012611.0001.8350043.0112769.92270D11 (variable)12∞2.000(Aperture S)1381.393203.2101.5891361.214-59.409150.2001527.883185.0361.4970081.716-33.995941.0001.8340037.21777.2322615.52518-48.290932.1871.7552027.619-29.43837D19(variable)2040.773063.3521.4970081.721-31.473641.0001.8350043.022-93.41414D22 (variable)23-26.116283.4231.8466623.824-15.438191.0001.8350043.0251918.42480BF [Lens Group Data]

[0302] GroupStarting SurfaceFocal LengthG11143.94G26-43.92G31344.60G42095.88G523-31.17 [Variable Distance Data]

[0303] WMTWMTInfinityInfinityInfinityShort DistanceShort DistanceShort Distancef51.25150.00243.75---Magnification----0.0560-0.1595-0.2488D0∞∞∞869.28838.20814.28D52.10038.22152.5442.10038.22152.544D1133.1707.4582.11833.1707.4582.118D194.52711.69022.4012.5013.7577.406D2219.87412.7122.00021.90020.64416.996BF14.63935.31250.24714.63935.31250.247 [Conditional Expression Corresponding Value]

[0304] f 4 / − f 2 = 2.1830 f 3 a / f 3 b = 0.5028 f 3 α / f 3 β = 0.6284 f 3 / − f 2 = 1.0155 f 3 / f 4 = 0.4652 m 12 / fw = 0.9843 m 34 / fw = 0.3488

[0305] FIG. 46A, FIG. 46B and FIG. 46C are each an aberration graph illustrating aberrations upon focusing on infinity in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 12. FIG. 47A, FIG. 47B and FIG. 47C are each an aberration graph illustrating aberrations upon focusing on short distance (close range) in a wide angle end state, in an intermediate focal length state, and in a telephoto end state of the zoom optical system having a vibration proof function according to Example 12. FIG. 48A, FIG. 48B, and FIG. 48C are each a meridional lateral aberration graph when shake compensation is performed in the wide angle end state, in the intermediate focal length state, and in the telephoto end state of the zoom optical system having a vibration proof function according to Example 12. It is apparent from respective aberration graphs that the zoom optical system according to Example 12 has an excellent image forming performance capable of correcting various aberrations successfully from the wide angle end state to the telephoto end state, and also has an excellent image forming performance also upon focusing on a short distant object.

[0306] According to Examples 1 to 11, the optical performance in the wide angle end state is improved, and thus a telephoto type zoom optical system having a wider angle of view is achieved. According to Examples 1 to 11, a telephoto type zoom optical system having a higher zooming rate is achieved. According to the Examples 9 to 12, a telephoto type zoom optical system having a small-sized vibration proof group is achieved.

[0307] In this specification, each example described above shows a specific example of each configuration, and the configuration are not limited thereto.

[0308] It should be noted that the following contents can be suitably employed within the range in which optical performance of the optical system of each configuration is not impaired.

[0309] Although a 4-groups configuration and a 5-groups configuration are described as examples of the numerical values of the zoom optical system in each configuration. However, the present application is not limited thereto, and the zoom optical systems with other number of groups (for example, 6 groups) configuration are also applicable. Specifically, there may be provided a configuration in which 2 or more lens groups having positive or negative refractive power are disposed between the first negative lens group and the second negative lens group. Also, there may be provided a configuration in which 2 or more lens groups having positive or negative refractive power are disposed on the object side with respect to the first negative lens group. Also, a configuration in which two or more lens groups having positive or negative refractive power disposed closer to an image than the second negative lens group is also applicable. Further, it is possible to add a lens or a lens group to a position closest to the object or a position closest to the image surface of the zoom optical system of each configuration. It should be noted that the lens group means a portion having at least one lens separated at an air distance that varies during zooming of the lens group.

[0310] In the zoom optical system of each configuration, the focusing lens group may be configured to focus from an infinite distant object to a short distant object by moving a single or a plurality of lens groups or a partial lens group in the optical axis direction instead of the at least part of lenses in the second negative lens group. The focusing lens group may be applied to autofocusing, and is also suitable to the motor driving for autofocusing (using a stepping motor or the like). The amount of change of the image surface at the time of focusing during imaging a movie may be suppressed by reducing an image surface movement coefficient by specifying the focal length of the second negative lens group to an adequate range.

[0311] The lens surface may be formed of a spherical surface or a flat surface, or even of an aspherical surface. In particular, aberration correction by using an aspherical surface for a positive lens component arranged so as to oppose the image side of the aperture stop enables reduction of the number of lenses of the lens group including the aperture stop (or the lens group disposed so as to oppose the image side of the aperture stop in the case where the aperture stop moves solely during zooming). In addition, adjustment of aberration correction and manufacture sensitivity is enabled by using the aspherical surface for the positive lens component disposed so as to oppose the image side of the aperture stop and also by using an air distance in the lens group including the aperture stop (or the lens group disposed so as to oppose the image side of the aperture stop in the case where the aperture stop moves solely during zooming). When the lens surface is a spherical surface or a flat surface, machining and assembly adjustment are easy. It is therefore preferable because deterioration of optical performance due to errors in machining and assembly adjustment is prevented. In addition, it is preferable because deterioration of descriptive performance is not much even when the image surface is displaced.

[0312] When the lens surface is an aspherical surface, the aspherical surface may be any of an aspherical surface formed by grinding, a glass mold aspherical surface formed of glass into an aspherical shape by a mold, and a composite type aspherical surface fabricated by forming a resin into an aspherical surface shape on a surface of glass. The lens surface may be a diffraction surface, and the lenses may be gradient index lenses (GRIN lenses) or plastic lenses.

[0313] The aperture stop is preferably disposed between the second lens group and the third lens group, but may be disposed in the third lens group or on the image side of the third lens group. Alternatively, a member as the aperture stop may not be provided and a lens frame may be used instead to perform the role of the aperture stop.

[0314] Each lens surface may be coated with an antireflection film having a high transmittance in a wide wavelength region for reducing flare and ghost and achieving a high contrast optical performance. Accordingly, the flare and the ghost may be reduced, and a high optical performance with a high contrast is achieved.EXPLANATION OF NUMERALS AND CHARACTERS

[0315] G1 first lens group (object side lens group) G2 second lens group (first negative lens group) G3 third lens group (intermediate lens group) G4 fourth lens group (second negative lens group) G5 fifth lens group (image side lens group) I image surface S aperture stop

Claims

1. A zoom optical system comprising: a first negative lens group having a negative refractive power; a second negative lens group disposed closer to an image than the first negative lens group; and an intermediate lens group disposed between the first negative lens group and the second negative lens group, wherein a distance between the first negative lens group and the second negative lens group changes during zooming, wherein a distance between the first negative lens group and the intermediate lens group changes, and a distance between the intermediate lens group and the second negative lens group changes during zooming, wherein the first negative lens group is movable so as to have a displacement component in a direction perpendicular to an optical axis, wherein at least part of the second negative lens group is movable along the optical axis during focusing, wherein a conditional expression, 0.50 < fGb / fGa < 2.60 , is satisfied, where, fGa : a focal length of the first negative lens group, and fGb : a focal length of the second negative lens group, and wherein a conditional expression, 0.40 < fGc / − fGa < 2.60 is satisfied, where, fGc : a focal length of the intermediate lens group.

2. The zoom optical system according to claim 1, further comprising a third negative lens group having a negative refractive power, which is disposed closer to an image than the second negative lens group, and the third negative lens group being fixed in its position on the optical axis during zooming.

3. The zoom optical system according to claim 1 or 2, further comprising a positive lens group having a positive refractive power, which is disposed between the first negative lens group and the second negative lens group, and a distance between the first negative lens group and the positive lens group and a distance between the positive lens group and the second negative lens group being changed during zooming.

4. The zoom optical system according to any one of claims 1 to 3, wherein the second negative lens group consists of a cemented lens of a positive lens and a negative lens.

5. The zoom optical system according to any one of claims 1 to 3, wherein the second negative lens group comprises a positive lens and a negative lens disposed in order from an object, an air distance is present between the positive lens and the negative lens, and a conditional expression, 0.001 < Dpn / − fGb < 0.400 is satisfied, where, Dpn : an air distance between the positive lens and the negative lens in the second negative lens group.

6. The zoom optical system according to any one of claims 1 to 5, comprising an object side lens group disposed on the object side with respect to the first negative lens group and having a positive refractive power, wherein a distance between the object side lens group and the first negative lens group changes during zooming.

7. The zoom optical system according to any one of claims 1 to 6, further comprising a first positive lens group having a positive refractive power, which is disposed closest to an object, and wherein a lens component disposed closest to an object consists of a single positive lens.

8. The zoom optical system according to any one of claims 1 to 7, comprising a first positive lens group having positive refractive power, wherein the first positive lens group consists of, in order from an object side, a positive lens, a negative lens and a positive lens.

9. The zoom optical system according to any one of claims 1 to 8, wherein a lens component disposed closest to an image consists of a single negative lens.

10. The zoom optical system according to any one of claims 1 to 9, wherein the first negative lens group includes at least partly a vibration proof group movable so as to have a displacement component in a direction perpendicular to an optical axis, and a conditional expression, 0.93 < fVR / fGa < 2.50 is satisfied, where, fVR : a focal length of the vibration proof group.

11. The zoom optical system according to any one of claims 1 to 10, wherein the first negative lens group comprises at least partly a vibration proof group movable so as to have a displacement component in a direction perpendicular to an optical axis, and the vibration proof group consists of a positive lens, a first negative lens, and a second negative lens disposed in order from an object, an air distance is present between the positive lens and the first negative lens, and an air distance is present between the first negative lens and the second negative lens.

12. The zoom optical system according to any one of claims 1 to 11, comprising an intermediate lens group disposed between the first negative lens group and the second negative lens group, wherein a distance between the first negative lens group and the intermediate lens group changes, and a distance between the intermediate lens group and the second negative lens group changes during zooming, and an aperture stop is disposed between the first negative lens group and the intermediate lens group.

13. The zoom optical system according to any one of claims 1 to 12, comprising an intermediate lens group disposed between the first negative lens group and the second negative lens group, wherein a distance between the first negative lens group and the intermediate lens group changes, and a distance between the intermediate lens group and the second negative lens group changes during zooming, and the intermediate lens group consists of the object side subgroup having a positive refractive power and the image side subgroup having a positive refractive power disposed in order from an object, and a lens component including a negative lens is disposed at a position closest to the object in the image side subgroup, and a conditional expression, 0.06 < fa / fb < 1.20 is satisfied, where, fa : a focal length of the object side subgroup, and fb : a focal length of the image side subgroup.

14. The zoom optical system according to any one of claims 1 to 13, comprising an intermediate lens group disposed between the first negative lens group and the second negative lens group, wherein a distance between the first negative lens group and the intermediate lens group changes, and a distance between the intermediate lens group and the second negative lens group changes during zooming, and the intermediate lens group consists of the object side subgroup having a positive refractive power and the image side subgroup having a positive refractive power disposed in order from an object, and an air distance between the object side subgroup and the image side subgroup is the maximum air distance between the air distance between lenses in the intermediate lens group, and a conditional expression, 0.06 < fα / fβ < 2.60 is satisfied, where, fα : a focal length of the object side subgroup, and fβ : a focal length of the image side subgroup.

15. The zoom optical system according to any one of claims 1 to 14, wherein the first negative lens group includes partly a vibration proof group movable so as to have a displacement component in a direction perpendicular to an optical axis, and the first negative lens group consists of a negative subgroup having a negative refractive power and the vibration proof group having a negative refractive power disposed in order from an object, and a lens component including a positive lens is disposed at a position closest to the image in the vibration proof group.

16. The zoom optical system according to any one of claims 1 to 15, comprising an intermediate lens group disposed between the first negative lens group and the second negative lens group, wherein a distance between the first negative lens group and the intermediate lens group changes, and a distance between the intermediate lens group and the second negative lens group changes during zooming, and a conditional expression, 0.20 < fGc / − fGb < 2.40 is satisfied, where, fGc : a focal length of the intermediate lens group.

17. The zoom optical system according to any one of claims 1 to 16, comprising an object side lens group disposed on the object side with respect to the first negative lens group and having a positive refractive power, wherein a distance between the object side lens group and the first negative lens group changes during zooming, and a conditional expression, 0.30 < mda / fw < 2.30 is satisfied, where, | mda | : an absolute value of the amount of change in distance from a lens surface closest to an image in the object side lens group to a lens surface closest to an object in the first negative lens group on the optical axis during zooming from the wide angle end state to the telephoto end state, and fw : a focal length of the zoom optical system in the wide angle end state.

18. The zoom optical system according to any one of claims 1 to 17, comprising an intermediate lens group disposed between the first negative lens group and the second negative lens group, wherein a distance between the first negative lens group and the intermediate lens group changes, and a distance between the intermediate lens group and the second negative lens group changes during zooming, and a conditional expression, 0.050 < mcb / fw < 0.750 is satisfied, where | mcb | : an absolute value of the amount of change in distance from a lens surface closest to an image in the intermediate lens group to a lens surface closest to an object in the second negative lens group on the optical axis during zooming from the wide angle end state to the telephoto end state, and fw : a focal length of the zoom optical system in the wide angle end state.

19. The zoom optical system according to any one of claims 1 to 18, comprising an aperture stop disposed between the first negative lens group and the second negative lens group, and a lens group having a positive lens component disposed so as to oppose the image side of the aperture stop, wherein a distance between the first negative lens group and a lens group having the positive lens component changes, and a distance between a lens group having the positive lens component and the second negative lens group changes during zooming, a conditional expression, 0.40 < fp / fGp < 3.60 is satisfied, where, fp : a focal length of the positive lens component, and fGp : a focal length of the lens group having the positive lens component.

20. The zoom optical system according to any one of claims 1 to 19, comprising an aperture stop disposed between the first negative lens group and the second negative lens group, and a lens group having a positive lens component disposed so as to oppose the image side of the aperture stop, wherein a distance between the first negative lens group and a lens group having the positive lens component changes, and a distance between a lens group having the positive lens component and the second negative lens group changes during zooming, a conditional expression, 0.40 < LS / LGp < 0.90 is satisfied, where, LS : a sum of air distances on the image side of the positive lens component in the lens group having the positive lens component, and LGp : a thickness of the lens group having the positive lens component on the optical axis.

21. An optical apparatus comprising the zoom optical system according to any one of claims 1 to 20.