Zoom optical system, optical apparatus and method for manufacturing the zoom optical system

A zoom optical system consisting of a first lens group having positive refractive power and a rear group comprising a plurality of lens groups, the lens groups being arranged in order from an object side along an optical axis, wherein

• upon zooming from a wide-angle end state to a telephoto end state, the first lens group moves to the object side along the optical axis and a space between the lens groups adjacent to each other changes,
• the first lens group comprises a front fixed group having a position fixed relative to an image surface upon focusing and a front focusing group that moves along the optical axis upon focusing, the groups being arranged in order from the object side along the optical axis, and
• the following conditional expressions are satisfied:
• 0.60<fP1/(−fF1)<1.00
• 0.80<(−fF1)/fw<1.40
• where
• fP1:
• a focal length of the front fixed group,
• fF1:
• a focal length of the front focusing group, and
• fw:
• a focal length of the zoom optical system in the wide-angle end state.

A method for manufacturing a zoom optical system consisting of a first lens group having positive refractive power and a rear group comprising a plurality of lens groups, the lens groups being arranged in order from an object side along an optical axis,

• the method comprises either the following step (A) or the following step (B):
• (A) arranging the lens groups in a lens barrel so that:
• a space between the lens groups adjacent to each other changes upon zooming,
• the plurality of lens groups in the rear group include a second lens group having positive refractive power and disposed closest to the object side in the rear group, and
• the following conditional expression is satisfied:
• 0.15<f2/f1<0.80
• where
• f1:
• a focal length of the first lens group, and
• f2:
• a focal length of the second lens group,
• (B) arranging the lens groups in a lens barrel so that:
• upon zooming from a wide-angle end state to a telephoto end state, the first lens group moves to the object side along the optical axis and a space between the lens groups adjacent to each other changes,
• the first lens group comprises a front fixed group having a position fixed relative to an image surface upon focusing and a front focusing group that moves along the optical axis upon focusing, the groups being arranged in order from the object side along the optical axis, and
• the following conditional expressions are satisfied:
• 0.60<fP1/(−fF1)<1.00
• 0.80<(−fF1)/fw<1.40
• where
• fP1:
• a focal length of the front fixed group,
• fF1:
• a focal length of the front focusing group, and
• fw:
• a focal length of the zoom optical system in the wide-angle end state.