Variable magnification optical system, optical device, and method for manufacturing variable magnification optical system

A variable magnification optical system comprising, in order from an object side, a first lens group having positive refractive power;

• a second lens group having negative refractive power;
• a third lens group having positive refractive power;
• 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 distance between the first lens group and the second lens group being increased, a distance between the second lens group and the third lens group being decreased, the third lens group being moved to the object side and a distance between the fourth lens group and the fifth lens group being varied;
• a V lens group having negative refractive power being movable with a movement component in a direction perpendicular to an optical axis;
• an F lens group being moved along the optical axis upon focusing;
• and
• the following conditional expression being satisfied:
• 0.28
• <
• (
• -
• fv
• )
• /
• f
• ⁢
• 3
• <
• 5.2
• where f3 denotes a focal length of the third lens group and fv denotes a focal length of the V lens group.

A variable magnification optical system comprising, in order from an object side, a first lens group having positive refractive power;

• a second lens group having negative refractive power;
• a third lens group having positive refractive power;
• 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 distance between the first lens group and the second lens group being increased, a distance between the second lens group and the third lens group being decreased, a distance between the third lens group and the fourth lens group being varied, and a distance between the fourth lens group and the fifth lens group being varied;
• an F lens group being moved along an optical axis upon focusing;
• and
• the following conditional expressions being satisfied:
• 5.5
• <
• f
• ⁢
• 1
• /
• fw
• <
• 9.
• 1.15
• <
• ff
• /
• f
• ⁢
• 3
• <
• 5.2
• where fw denotes a focal length of the variable magnification optical system in the wide-angle end state, f1 denotes a focal length of the first lens group, f3 denotes a focal length of the third lens group, and ff denotes a focal length of the F lens group.

A method for manufacturing a variable magnification optical system, comprising:

• arranging, 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;
• and
• constructing such that at least one of the following features (A) or (B) is provided:
• (A) upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group is increased, a distance between the second lens group and the third lens group is decreased, the third lens group is moved to the object side and a distance between the fourth lens group and the fifth lens group is varied;
• a V lens group having negative refractive power is movable with a movement a component in a direction perpendicular to an optical axis;
• an F lens group is moved along the optical axis upon focusing;
• and
• the following conditional expression is satisfied:
• 0.28
• <
• (
• -
• fv
• )
• /
• f
• ⁢
• 3
• <
• 5.2
• where f3 denotes a focal length of the third lens group and fv denotes a focal length of the V lens group,
• (B) upon zooming from a wide-angle end state to a telephoto end state, a distance between the first lens group and the second lens group is increased, a distance between the second lens group and the third lens group is decreased, a distance between the third lens group and the fourth lens group is varied and a distance between the fourth lens group and the fifth lens group is varied;
• an F lens group is moved along an optical axis upon focusing;
• and
• the following conditional expressions are satisfied:
• 5.5
• <
• f
• ⁢
• 1
• /
• fw
• <
• 9.
• 1.15
• <
• ff
• /
• f
• ⁢
• 3
• <
• 5
• .
• 2
• ⁢
• 0
• ⁢
• 0
• where fw denotes a focal length of the variable magnification optical system in the wide-angle end state, f1 denotes a focal length of the first lens group, f3 denotes the focal length of the third lens group and ff denotes a focal length of the F lens group.