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;
• a second lens group having negative refractive power;
• an intermediate group which has at least one lens group and which has positive refractive power;
• a focusing lens group having negative refractive power;
• and a rear group having at least one lens group, which are aligned in order from an object side along an optical axis, wherein
• when zooming is performed, intervals between neighboring lens groups are changed,
• the focusing lens group moves along the optical axis when focusing is performed, and
• the following conditional expressions are satisfied,
• 0.
• 3
• ⁢
• 0
• <
• (
• -
• f
• ⁢
• 2
• )
• /
• fMt
• <
• 0
• .80
• 0.01
• <
• Bfw
• /
• fw
• <
• 0.
• 9
• ⁢
• 5
• where f2 denotes a focal length of the second lens group,
• fMt denotes a focal length of the intermediate group in a telephoto end state,
• Bfw denotes a back focal length of the zoom optical system in a wide angle end state, and
• fw denotes a focal length of the zoom optical system in the wide angle end state.

A method for manufacturing a zoom optical system comprising 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 negative refractive power, which are aligned in order from an object side along an optical axis, comprises;
• arranging the lens groups in a lens barrel so that:
• when zooming is performed, intervals between neighboring lens groups are changed,
• the fourth lens group is a focusing lens group which moves along the optical axis when focusing is performed, and
• the following conditional expression is satisfied,
• 0.
• 1
• ⁢
• 1
• <
• f
• ⁢
• 4
• /
• f
• ⁢
• 5
• <
• 0
• .
• 7
• ⁢
• 0
• where f4 denotes a focal length of the fourth lens group, and
• f5 denotes a focal length of the fifth lens group.