Zoom lens, image pickup apparatus, and image pickup system
A zoom lens includes, in order from an object side to an image side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power, a distance between the first lens unit and the second lens unit changing during zooming. A predetermined condition is satisfied.
1. A zoom lens comprising, in order from an object side to an image side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power, a distance between the first lens unit and the second lens unit changing during zooming,
wherein the following conditional expressions are satisfied:
0.010< fw/Lw< 0.050,
8.0< m 1/ z< 40.0, and
−3.5< f 1/ fw<− 0.8
where fw is a focal length of the zoom lens at a wide-angle end, Lw is an overall optical length at the wide-angle end, m1 is a moving amount of the first lens unit during zooming from the wide-angle end to a telephoto end, z is a magnification varying ratio of the zoom lens, and f1 is a focal length of the first lens unit.
2. The zoom lens according to claim 1 , wherein the following conditional expression is satisfied:
3.5< f 2/ fw< 10.0
where f2 is a focal length of the second lens unit.
3. The zoom lens according to claim 1 , wherein the first lens unit includes, in order from the object side to the image side, a first partial lens unit and a second partial lens unit, and
wherein the second partial lens unit moves in an optical axis direction during focusing.
4. The zoom lens according to claim 3 , wherein the following conditional expression is satisfied:
−20.0< f 1 b/fw<− 6.0
where f1b is a focal length of the second partial lens unit.
5. The zoom lens according to claim 1 , wherein the following conditional expression is satisfied:
−7.0< fG 1 n/fw<− 2.0
where fG1n is a focal length of a negative lens disposed closest to the object side among negative lenses included in the zoom lens.
6. The zoom lens according to claim 1 , wherein the following conditional expression is satisfied:
2.0< fG 1 p/fw< 6.2
where fG1p is a focal length of a positive lens disposed closest to the object side among positive lenses included in the zoom lens.
7. The zoom lens according to claim 1 , wherein the first lens unit includes four or more negative lenses and two or more positive lenses.
8. The zoom lens according to claim 1 , wherein the first lens unit includes, in order from the object side to the image side, a negative lens, a negative lens, a negative lens, a positive lens, a negative lens, a positive lens, and a negative lens.
9. The zoom lens according to claim 1 , wherein the second lens unit includes, in order from the object side to the image side, a third partial lens unit and a fourth partial lens unit, and
wherein a distance between the third partial lens unit and the fourth partial lens unit changes during zooming.
10. The zoom lens according to claim 1 , wherein the second lens unit includes, in order from the object side to the image side, a third partial lens unit, a fourth partial lens unit, and a fifth partial lens unit, and
wherein a distance between adjacent partial lens units changes during zooming.
11. The zoom lens according to claim 1 , wherein the following conditional expression is satisfied:
50.0°<ω w
where ωw is a half angle of view at the wide-angle end.
12. An image pickup apparatus comprising:
a zoom lens; and
an image sensor configured to receives an image formed by the zoom lens,
wherein the zoom lens includes, in order from an object side to an image side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power, a distance between the first lens unit and the second lens unit changing during zooming, and
wherein the following conditional expressions are satisfied:
0.010< fw/Lw< 0.050,
8.0< m 1/ z< 40.0, and
−3.5< f 1/ fw<− 0.8
where fw is a focal length of the zoom lens at a wide-angle end, Lw is an overall optical length at the wide-angle end, m1 is a moving amount of the first lens unit during zooming from the wide-angle end to a telephoto end, z is a magnification varying ratio of the zoom lens, and f1 is a focal length of the first lens unit.
13. An image pickup system comprising:
a zoom lens; and
a controller configured to control the zoom lens during zooming,
wherein the zoom lens includes, in order from an object side to an image side, a first lens unit having a negative refractive power and a second lens unit having a positive refractive power, a distance between the first lens unit and the second lens unit changing during zooming, and
wherein the following conditional expressions are satisfied:
0.010< fw/Lw< 0.050,
8.0< m 1/ z< 40.0, and
−3.5< f 1/ fw<− 0.8
where fw is a focal length of the zoom lens at a wide-angle end, Lw is an overall optical length at the wide-angle end, m1 is a moving amount of the first lens unit during zooming from the wide-angle end to a telephoto end, z is a magnification varying ratio of the zoom lens, and f1 is a focal length of the first lens unit.
14. The image pickup system according to claim 13 , wherein the controller is configured separately from the zoom lens, and includes a transmitter configured to transmit a control signal for controlling the zoom lens.
15. The image pickup system according to claim 13 , wherein the controller is configured separately from the zoom lens and has an operation unit for operating the zoom lens.
16. The image pickup system according to claim 13 , further comprising a display unit configured to display information of a zoom of the zoom lens.