Zoom lens and image pickup apparatus
Provided is a zoom lens consisting of, in order from an object side to an image side: a positive front lens unit configured not to move for zooming; a plurality of magnification-varying lens units including two magnification-varying lens units having negative refractive powers configured to move for zooming; and a positive rear lens unit configured not to move for zooming, in which a focal length of the front lens unit, a focal length of a magnification-varying lens unit having a negative refractive power and arranged closest to the object side in the plurality of magnification-varying lens units, a focal length of a magnification-varying lens unit having a negative refractive power and arranged closest to the image side in the plurality of magnification-varying lens units, and a focal length of the rear lens unit are suitably set.
1. A zoom lens comprising a plurality of lens units, wherein the plurality of lens units consists of in order from an object side to an image side:
a front lens unit having a positive refractive power and configured not to move for zooming;
a plurality of moving lens units, including two lens units having negative refractive powers, configured to move for zooming; and
a rear lens unit having a positive refractive power and configured not to move for zooming,
wherein conditional expressions
2.7<| f 2 n/fr|< 6.0;
0.5<| ff/f 1 n|< 2.3; and
0.140< m 1 n/L≤ 0.237
are satisfied where ff is a focal length of the front lens unit, f1n is a focal length of a lens unit arranged closest to the object side of all negative lens units in the plurality of moving lens units, f2n is a focal length of a lens unit arranged closest to the image side of all negative lens units in the plurality of moving lens units, fr is a focal length of the rear lens unit, m1n is an absolute value of a maximum movement amount of the lens unit having the focal length f1n for zooming, and L is a distance from a vertex of a surface, on the object side, of a lens closest to the object side in the front lens unit to an image plane.
2. The zoom lens according to claim 1 , wherein a conditional expression
−1.0<β r<− 0.2
is satisfied where βr is a lateral magnification of the rear lens unit.
3. An image pickup apparatus comprising:
a zoom lens of claim 1 ; and
an image pickup element configured to pick up an image formed by the zoom lens.
4. A zoom lens comprising a plurality of lens units, wherein the plurality of lens units consists of in order from an object side to an image side:
a front lens unit having a positive refractive power and configured not to move for zooming;
a plurality of moving lens units, including two lens units having negative refractive powers, configured to move for zooming; and
a rear lens unit having a positive refractive power and configured not to move for zooming,
wherein conditional expressions
2.7<| f 2 n/fr|< 6.0;
0.5<| ff/f 1 n|< 2.3; and
0.05< BF/Lr< 0.35
are satisfied where ff is a focal length of the front lens unit, f1n is a focal length of a lens unit arranged closest to the object side of all negative lens units in the plurality of moving lens units, f2n is a focal length of a lens unit arranged closest to the image side of all negative lens units in the plurality of moving lens units, fr is a focal length of the rear lens unit, Lr is a distance from a vertex of a surface, on the object side, of a lens closest to the object side in the rear lens unit to an image plane, and BF is a distance from a vertex of a surface, on the image side, of a lens closest to the image side in the rear lens unit to the image plane.
5. An image pickup apparatus comprising:
a zoom lens of claim 4 ; and
an image pickup element configured to pick up an image formed by the zoom lens.
6. A zoom lens comprising a plurality of lens units, wherein the plurality of lens units consists of in order from an object side to an image side:
a front lens unit having a positive refractive power and configured not to move for zooming;
a plurality of moving lens units, including two lens units having negative refractive powers, configured to move for zooming; and
a rear lens unit having a positive refractive power and configured not to move for zooming,
wherein the rear lens unit has a front principal point located on the object side with respect to a vertex of a surface, on the object side, of a lens closest to the object side in the rear lens unit, and
wherein conditional expressions
2.7<| f 2 n/fr|< 6.0;
0.5<| ff/f 1 n|< 2.3; and
0.08< o 1 r/Lr< 0.20
are satisfied where ff is a focal length of the front lens unit, f1n is a focal length of a lens unit arranged closest to the object side of all negative lens units in the plurality of moving lens units, f2n is a focal length of a lens unit arranged closest to the image side of all negative lens units in the plurality of moving lens units, fr is a focal length of the rear lens unit, o1r is a distance from the vertex of the surface to the front principal point, and Lr is a distance from the vertex of the surface to an image plane.
7. An image pickup apparatus comprising:
a zoom lens of claim 6 ; and
an image pickup element configured to pick up an image formed by the zoom lens.
8. A zoom lens consisting of in order from an object side to an image side:
a front lens unit having a positive refractive power and configured not to move for zooming;
a plurality of moving lens units, including two lens units having negative refractive powers, configured to move for zooming; and
a rear lens unit having a positive refractive power and configured not to move for zooming,
wherein the rear lens unit consists of a front lens sub-unit having a positive refractive power and a rear lens sub-unit having a negative refractive power with a largest gap therebetween in the rear lens unit, and
wherein conditional expressions
2.7<| f 2 n/fr|< 6.0;
0.5<| ff/f 1 n|< 2.3; and
0.1<| frp/frn|< 0.7
are satisfied where ff is a focal length of the front lens unit, f1n is a focal length of a lens unit arranged closest to the object side of all negative lens units in the plurality of moving lens units, f2n is a focal length of a lens unit arranged closest to the image side of all negative lens units in the plurality of moving lens units, fr is a focal length of the rear lens unit, frp is a focal length of the front lens sub-unit, and frn is a focal length of the rear lens sub-unit.
9. The zoom lens according to claim 8 , wherein the front lens sub-unit includes a plurality of lenses each having a positive refractive power and an Abbe number νd that satisfies a conditional expression
75.0< νd< 100,
where the Abbe number νd is represented by an expression
νd =( Nd− 1)/( NF−NC ),
where NF, Nd, and NC are refractive indices with respect to an F-line (wavelength of 486.1 nm), a d-line (wavelength of 587.6 nm), and a C-line (wavelength of 656.3 nm) as Fraunhofer lines, respectively.
10. An image pickup apparatus comprising:
a zoom lens of claim 8 ; and
an image pickup element configured to pick up an image formed by the zoom lens.