Inverse telephoto large aperture wide angle lens
AssigneeNikon Corporation
InventorsKenji Hori, Wataru Tatsuno
Life of this patent
Estimating the term…
Abstract
An inverse telephoto large aperture wide angle lens comprises a first lens group with a negative refractive power, a second lens group with a positive refractive power, a stop, a third lens group with a negative refractive power, and a fourth lens group with a positive refractive power arranged in the named order from a side of an object, in which for focusing on a near object from infinity the first lens group is fixed with respect to an image surface, and the second, third, and fourth lens groups are moved along an optical axis thereof toward the object such that a space between the first lens group and the second group and a space between the second lens group and the third lens group decrease, but a space between the third lens group and the fourth lens group increases.
Claims6
An inverse telephoto large aperture wide angle lens comprising a first lens group with a negative refractive power, a second lens group with a positive refractive power, a stop, a third lens group with a negative refractive power, and a fourth lens group with a positive refractive power arranged in the order from an object side, wherein for focusing on a near object from infinity said first lens group is fixed with respect to an image surface, and said second, third, and fourth lens groups are moved along an optical axis thereof toward said object such that a space between said first lens group and said second lens group and a space between said second lens group and said third lens group decrease, but a space between said third lens group and said fourth lens group increases.
A large aperture wide angle lens comprising a first lens group with a negative refractive power, a second lens group with a positive refractive power, a third lens group with a negative refractive power, and a fourth lens group with a positive refractive power arranged in the order from an object side, wherein for focusing on a near object from infinity said first lens group is fixed with respect to an image surface, and said second, third, and fourth lens groups are moved along an optical axis thereof toward said object.
Dependencies are inferred from the claim text.