Optical system, optical apparatus and method for manufacturing the optical system

An optical system comprising:

• a first lens group, a first focusing lens group having negative refractive power, a second focusing lens group having positive refractive power, and a succeeding lens group having negative refractive power, which are arranged in order from an object side along an optical axis,
• the first focusing lens group and the second focusing lens group moving along the optical axis in loci, which are different from each other, in focusing,
• the optical system further comprising an aperture stop which is arranged on the object side relative to the first focusing lens group, wherein
• the following conditional expressions are satisfied:
• 0.6
• <
• fF
• ⁢
• 2
• /
• (
• -
• fR
• )
• <
• 1.1
• 0.5
• <
• Lre
• /
• Lfr
• <
• 4
• .
• 0
• ⁢
• 0
• where fF2:
• a focal length of the second focusing lens group,
• fR:
• a focal length of the succeeding lens group,
• Lfr:
• a distance, on the optical axis, from a lens surface of the optical system, which is closest to the object side, to the aperture stop, and
• Lre:
• a distance, on the optical axis, from the aperture stop to an image surface.

An optical system comprising:

• a first lens group, a first focusing lens group having negative refractive power, and a second focusing lens group having positive refractive power, which are arranged in order from an object side along an optical axis,
• the first focusing lens group and the second focusing lens group moving along the optical axis in loci, which are different from each other, in focusing,
• the following conditional expressions are satisfied:
• f
• ⁢
• 1
• /
• ❘
• "\[LeftBracketingBar]"
• f
• ⁢
• 1
• ⁢
• R
• ❘
• "\[RightBracketingBar]"
• <
• 1.
• 0.5
• <
• Lre
• /
• Lfr
• <
• 4
• .
• 0
• ⁢
• 0
• where f1:
• a focal length of the first lens group,
• f1R:
• a combined focal length of a lens group arranged on an image side relative to the first lens group upon focusing on infinity,
• Lfr:
• a distance, on the optical axis, from a lens surface of the optical system, which is closest to the object side, to the aperture stop, and
• Lre:
• a distance, on the optical axis, from the aperture stop to an image surface.

A method for manufacturing an optical system comprising a first lens group, a first focusing lens group having negative refractive power, a second focusing lens group having positive refractive power, and a succeeding lens group having negative refractive power, which are arranged in order from an object side along an optical axis, comprises a step of disposing the lens groups in a lens barrel so that;

• the first focusing lens group and the second focusing lens group move along the optical axis in loci, which are different from each other, in focusing,
• the optical system further comprises an aperture stop which is arranged on the object side relative to the first focusing lens group, and
• the following conditional expressions are satisfied:
• 0.6
• <
• fF
• ⁢
• 2
• /
• (
• -
• fR
• )
• <
• 1.1
• 0.5
• <
• Lre
• /
• Lfr
• <
• 4
• .
• 0
• ⁢
• 0
• where fF2:
• a focal length of the second focusing lens group,
• fR:
• a focal length of the succeeding lens group,
• Lfr:
• a distance, on the optical axis, from a lens surface of the optical system, which is closest to the object side, to the aperture stop, and
• Lre:
• a distance, on the optical axis, from the aperture stop to an image surface.

A method for manufacturing an optical system comprising a first lens group, a first focusing lens group having negative refractive power, and a second focusing lens group having positive refractive power, which are arranged in order from an object side along an optical axis, comprises a step of disposing the lens groups in a lens barrel so that;

• the first focusing lens group and the second focusing lens group move along the optical axis in loci, which are different from each other, in focusing, and
• the following conditional expressions are satisfied:
• f
• ⁢
• 1
• /
• ❘
• "\[LeftBracketingBar]"
• f
• ⁢
• 1
• ⁢
• R
• ❘
• "\[RightBracketingBar]"
• <
• 1.
• 0.5
• <
• Lre
• /
• Lfr
• <
• 4
• .
• 0
• ⁢
• 0
• where f1:
• a focal length of the first lens group,
• f1R:
• a combined focal length of a lens group arranged on an image side relative to the first lens group upon focusing on infinity,
• Lfr:
• a distance, on the optical axis, from a lens surface of the optical system, which is closest to the object side, to the aperture stop, and
• Lre:
• a distance, on the optical axis, from the aperture stop to an image surface.