Zoom optical system, optical apparatus and method for manufacturing the zoom optical system
A zoom optical system (ZL) comprises: a first lens group (G 1 ) disposed closest to an object and having a positive refractive power; an aperture stop (S) disposed closer to an image than the first lens group (G 1 ); a positive lens component disposed so as to oppose the image side of the aperture stop (S); and a lens group (G 3 ) having the positive lens component, wherein a distance between the first lens group (G 1 ) and the lens group (G 3 ) having the positive lens component changes during zooming, at least one lens surface of the positive lens component has an aspherical surface, and the following 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 (G 3 ) having the positive lens component.
1 . A zoom optical system, comprising:
an aperture stop,
a first lens group having positive refractive power, a second lens group having negative refractive power and a third lens group having positive refractive power, disposed in order from an object and the first lens group being disposed closest to the object, wherein
during zooming, a distance between the first lens group and the second lens group is varied, a distance between the second lens group and the third lend group is varied, and the first lens group is moved,
the aperture stop is disposed between the second lens group and the third lens group,
the third lens group has a positive lens component which is disposed closest to the object in the third lens group,
at least one surface of the positive lens component is aspherical, and
the following conditional expressions are satisfied:
0.40< fp/fGp< 3.60
0.40< LS/LGp< 3.60
where
fp: a focal length of the positive lens component,
fGp: a focal length of the third lens group,
LS: a sum of air distances on the image side of the positive lens component in the third lens group, and
LGp: a thickness of the third lens group on the optical axis.
2 . The zoom optical system according to claim 1 , further comprising:
an image-side negative lens group having negative refractive power and disposed at a position closer to an image than the third lens group, and
a final lens group disposed next to the image-side negative lens group on an image side and also disposed closest to the image,
during zooming, a distance between the third lens group and the image-side negative lens group and a distance between the image-side negative lens group and the final lens group are varied, and
during zooming, the final lens group is fixed in an optical axis direction.
3 . The zoom optical system according to claim 2 , wherein,
during focusing, the image-side negative lens group is moved.
4 . The zoom optical system according to claim 1 , wherein
the third lens group consists of four or five lenses.
5 . The zoom optical system according to claim 1 , further comprising:
an image-side negative lens group disposed at a position closer to an image than the third lens group and having negative refractive power, wherein
during zooming, a distance between the third lens group and the image-side negative lens group changes, and
the following conditional expression is satisfied:
0.40< fGp /(− fGb )<2.40
where
fGb: a focal length of the image-side negative lens group.
6 . An optical apparatus comprising:
the zoom optical system according to claim 1 .
7 . The zoom optical system according to claim 1 , wherein an image-side lens group is disposed next to an image side of the third lens group, and consists of a positive lens and a negative lens disposed in order from the object.
8 . The zoom optical system according to claim 7 , wherein
the image-side lens group has negative refractive power, and
the following conditional expression is satisfied:
0.40< fGp /(− fGb )<2.40
where
fGb: a focal length of the image-side lens group.
9 . A zoom optical system, comprising:
a first lens group having positive refractive power, a second lens group having negative refractive power and a third lens group having positive refractive power, disposed in order from an object and the first lens group being disposed closest to the object, wherein
during zooming, a distance between the first lens group and the second lens group is varied, a distance between the second lens group and the third lend group is varied, and the first lens group is moved,
the third lens group has a positive lens component which is disposed closest to the object in the third lens group,
an image-side lens group is disposed next to an image side of the third lens group, and consists of a positive lens and a negative lens dispose in order from the object,
an air distance is present between the positive lens and the negative lens,
during zooming, a distance between the third lens group and the image-side lens group is varied,
the image-side lens group is moved during focusing,
the second lens group is movable with a movement component perpendicular to an optical axis, and
the following conditional expression 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 third lens group.
10 . The zoom optical system according to claim 9 , wherein
the following conditional expression is satisfied:
0.40< fGp /(− fGa )<2.60
where
fGa: a focal length of the second lens group.
11 . An optical apparatus comprising:
the zoom optical system according to claim 9 .
12 . A zoom optical system, comprising:
an aperture stop,
a first lens group having positive refractive power, a second lens group having negative refractive power and a third lens group having positive refractive power, disposed in order from an object and the first lens group being disposed closest to the object, wherein
during zooming, a distance between the first lens group and the second lens group is varied, a distance between the second lens group and the third lend group is varied, and the first lens group is moved,
the aperture stop is disposed between the second lens group and the third lens group,
the third lens group consists of an object-side subgroup having positive refractive power and an image-side subgroup having positive refractive power disposed in order from the object,
the third lens group has a positive lens component which is disposed closest to the object in the third lens group,
at least one surface of the positive lens component is aspherical,
an air distance between the object-side subgroup and the image-side subgroup is a maximum air distance among all air distances between lenses in the third lens group, and
the following conditional expressions are satisfied:
0.40< fp/fGp< 3.60
0.06< fα/fβ< 2.60
where
fp: a focal length of the positive lens component,
fGp: a focal length of the third lens group,
fα: a focal length of the object-side subgroup, and
fβ: a focal length of the image-side subgroup.
13 . The zoom optical system according to claim 12 , wherein
the following conditional expression is satisfied:
0.70 <fp/fGp< 1.90.
14 . The zoom optical system according to claim 12 , further comprising:
an image-side negative lens group having negative refractive power disposed at a position closer to an image than the third lens group, wherein
during zooming, a distance between the third lens group and the image-side negative lens group is varied, and
during focusing, the image-side negative lens group is moved.
15 . The zoom optical system according to claim 12 , wherein
the following conditional expression is satisfied:
0.40< fGp /(− fGa )<2.60
where
fGa: a focal length of the second lens group.
16 . An optical apparatus comprising:
the zoom optical system according to claim 12 .