Zoom lens and apparatus having the same
AssigneeCanon Kabushiki Kaisha
InventorSatoshi Umehara
Life of this patent
Estimating the term…
Abstract
A zoom lens includes in order from an object side, a negative first lens unit and a rear lens unit including one or more lens units, an interval between adjacent lens units being changed during zooming, in which the first lens unit and the one or more lens units can be set to first, second and third zoom states, in which angles of view at first and second image heights at the first zoom state are respectively 160° or larger, in which a distortion at the first image height at the third zoom state is −30% or more, and the first image height, the second image height, a total length of the zoom lens at a wide angle end, and a focal length at the wide angle end are appropriately set.
Claims28
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 rear lens group including four or more lens units, an interval between adjacent lens units being changed during zooming,
- wherein the rear lens group includes a second lens unit, and an aperture stop disposed on the image side of the second lens unit,
- wherein the second lens unit is configured to move during focusing,
- wherein an angle of view is 160° or larger at a maximum image height and a second image height at a wide angle end and an intermediate focal length,
- wherein the following inequalities are satisfied,
- 1.5<H1/H2<3.0,
- 5.0<Lw/fw<22.5, and
- −30%<Vt<30%
- where H1 represents the maximum image height, H2 represents the second image height, Lw represents a distance from a lens surface closest to an object to an image plane at the wide angle end, fw represents a focal length at the wide angle end, and Vt represents a distortion amount at the maximum image height at a telephoto end with a reference of a perspective projection,
- wherein the first lens unit includes a first negative lens having a negative refractive power disposed closest to an object, and
- wherein the following inequality is satisfied,
- 1.9<G1Nd<2.5
- where G1Nd represents a refractive index of a material of the first negative lens.
Dependencies are inferred from the claim text.