Zoom lens system, optical apparatus and method for manufacturing zoom lens system
A zoom lens system includes, in order from an object side: a first lens group having positive refractive power; a second lens group having negative refractive power; a third lens group having positive refractive power; a fourth lens group having negative refractive power; and a fifth lens group having positive refractive power. Upon zooming from a wide-angle end state to a telephoto end state, a position of the first lens group is fixed. At least a portion of any one of the lens groups is moved in a direction including a component perpendicular to an optical axis, and a given conditional expression is satisfied, thereby providing a zoom lens system capable of excellently suppressing variation in aberrations upon zooming and upon correcting an image blur, an optical apparatus including the zoom lens system, and a method for manufacturing the zoom lens system.
1. A zoom lens system comprising, in order from an object side:
a first lens group having positive refractive power;
a second lens group having negative refractive power;
a third lens group having positive refractive power;
a fourth lens group having negative refractive power; and
a fifth lens group having positive refractive power,
upon zooming from a wide-angle end state to a telephoto end state, a position of the first lens group being fixed,
at least a portion of any one of the lens groups being movable in a direction including a component perpendicular to an optical axis, and
the following conditional expressions being satisfied:
5.20 <f 1/(− f 2)<8.00
0.50 <f 2 /f 4<0.85
where f 1 denotes a focal length of the first lens group, f 2 denotes a focal length of the second lens group, and f 4 denotes a focal length of the fourth lens group.
2. The zoom lens system according to claim 1 , wherein at least a portion of the third lens group is movable in a direction including a component perpendicular to the optical axis.
3. The zoom lens system according to claim 1 , wherein the following conditional expression is satisfied:
0.20 <f 3 /f 5<0.80
where f 3 denotes a focal length of the third lens group, and f 5 denotes a focal length of the fifth lens group.
4. The zoom lens system according to claim 1 , wherein the fourth lens group is moved upon carrying out focusing from an infinity object to a close object.
5. The zoom lens system according to claim 1 , wherein the following conditional expression is satisfied:
0.20<(− f 4)/ f 5<0.90
where f 4 denotes the focal length of the fourth lens group, and f 5 denotes a focal length of the fifth lens group.
6. The zoom lens system according to claim 1 , wherein a position of the third lens group is fixed upon zooming from the wide-angle end state to the telephoto end state.
7. The zoom lens system according to claim 1 , wherein distances between adjacent lens groups are varied upon zooming from the wide-angle end state to the telephoto end state.
8. The zoom lens system according to claim 1 , wherein an aperture stop is disposed between the second lens group and the fourth lens group.
9. A zoom lens system comprising, in order from an object side:
a first lens group having positive refractive power;
a second lens group having negative refractive power;
a third lens group having positive refractive power;
a fourth lens group having negative refractive power; and
a fifth lens group having positive refractive power,
upon zooming from a wide-angle end state to a telephoto end state, a position of the first lens group being fixed,
at least a portion of any one of the lens groups being movable in a direction including a component perpendicular to an optical axis, and
the following conditional expressions being satisfied:
0.44 <f 2 /f 4<1.00
0.20<(− f 2)/ f 5<0.50
where f 2 denotes a focal length of the second lens group, f 4 denotes a focal length of the fourth lens group, and f 5 denotes a focal length of the fifth lens group.
10. The zoom lens system according to claim 1 , wherein the following conditional expression is satisfied:
0.20<(− f 2)/ f 5<0.50
where f 2 denotes the focal length of the second lens group, and f 5 denotes a focal length of the fifth lens group.
11. The zoom lens system according to claim 1 , wherein the following conditional expression is satisfied:
3.00 <f 1 /f 3<5.00
where f 1 denotes the focal length of the first lens group, and f 3 denotes a focal length of the third lens group.
12. The zoom lens system according to claim 1 , wherein the following conditional expression is satisfied:
2.00 <f 1/(− f 4)<5.00
where f 1 denotes the focal length of the first lens group, and f 4 denotes the focal length of the fourth lens group.
13. An optical apparatus equipped with the zoom lens system according to claim 1 .
14. The zoom lens system according to claim 9 , wherein the following conditional expression is satisfied:
0.50 <f 2 /f 4<0.85
where f 2 denotes the focal length of the second lens group, and f 4 denotes the focal length of the fourth lens group.
15. The zoom lens system according to claim 9 , wherein the following conditional expression is satisfied:
3.00 <f 1 /f 3<5.00
where f 1 denotes a focal length of the first lens group, and f 3 denotes a focal length of the third lens group.
16. The zoom lens system according to claim 9 , wherein the following conditional expression is satisfied:
2.00 <f 1/(− f 4)<5.00
where f 1 denotes a focal length of the first lens group, and f 4 denotes the focal length of the fourth lens group.
17. An optical apparatus equipped with the zoom lens system according to claim 9 .
18. A method for manufacturing a zoom lens system including, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, the method comprising steps of:
disposing the first lens group, the second lens group, and the fourth lens group with the following conditional expressions being satisfied:
5.20 <f 1/(− f 2)<8.00
0.50 <f 2 /f 4<0.85
where f 1 denotes a focal length of the first lens group, f 2 denotes a focal length of the second lens group, and f 4 denotes a focal length of the fourth lens group;
the first lens group further being disposed so as to be fixed upon zooming from a wide-angle end state to a telephoto end state; and
at least a portion of any one of the lens groups being disposed so as to be movable in a direction including a component perpendicular to an optical axis.
19. The method according to claim 18 , wherein
at least a portion of the third lens group is movable in the direction including a component perpendicular to the optical axis.
20. The method according to claim 18 , further comprising a step of:
satisfying the following conditional expression:
0.20 <f 3 /f 5<0.80
where f 3 denotes a focal length of the third lens group, and f 5 denotes a focal length of the fifth lens group.
21. The method according to claim 18 , further comprising a step of:
satisfying the following conditional expression:
0.20<(− f 4)/ f 5<0.90
where f 4 denotes the focal length of the fourth lens group, and f 5 denotes a focal length of the fifth lens group.
22. A method for manufacturing a zoom lens system including, in order from an object side, a first lens group having positive refractive power, a second lens group having negative refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power, the method comprising steps of:
disposing the second lens group, the fourth lens group and the fifth lens group with the following conditional expressions being satisfied:
0.44 <f 2 /f 4<1.00
0.20<(− f 2)/ f 5<0.50
where f 2 denotes a focal length of the second lens group, f 4 denotes a focal length of the fourth lens group, and f 5 denotes a focal length of the fifth lens group;
disposing the first lens group so as to be fixed upon zooming from a wide-angle end state to a telephoto end state; and
disposing at least a portion of any one of the lens groups so as to be moveable in a direction including a component perpendicular to an optical axis.
23. The method according to claim 22 , further comprising a step of:
satisfying the following conditional expression:
3.00 <f 1 /f 3<5.00
where f 1 denotes a focal length of the first lens group, and f 3 denotes a focal length of the third lens group.
24. The method according to claim 22 , further comprising a step of:
satisfying the following conditional expression:
2.00 <f 1/(− f 4)<5.00
where f 1 denotes a focal length of the first lens group, and f 4 denotes the focal length of the fourth lens group.
25. A zoom lens system comprising, in order from an object side:
a first lens group having positive refractive power;
a second lens group having negative refractive power;
a third lens group having positive refractive power;
a fourth lens group having negative refractive power; and
a fifth lens group having positive refractive power,
upon zooming from a wide-angle end state to a telephoto end state, a position of the first lens group being fixed,
upon zooming from the wide-angle end state to the telephoto end state, a position of the third lens group being fixed,
at least a portion of any one of the lens groups being movable in a direction including a component perpendicular to an optical axis, and
the following conditional expression being satisfied:
5.20 <f 1/(− f 2)<8.00
where f 1 denotes a focal length of the first lens group, and f 2 denotes a focal length of the second lens group.