Canon Kabushiki Kaisha

Koichi Sakuma

Tomoyuki Nakamura

Kei Kinoshita

Provided is a lens apparatus attachable and removable to a camera apparatus, the lens apparatus comprising a communication device configured to transmit, to an external device, information for light amount compensation of image data obtained by image pickup in the camera apparatus, in which the information includes information of a coefficient Aof a term of 0-th-order with respect to an image height in a polynomial of n-th-order with respect to the image height, and in which a conditional expression0.7<()×(())<1.3is satisfied where A(Z) represents the coefficient Aat a zoom state Z, F(Z) represents an effective F-number at the zoom state Z, and Fw represents an effective F-number at a wide angle end.

Lens apparatus, image pickup apparatus, processing apparatus, and camera apparatus

Provided is a lens apparatus attachable and removable to a camera apparatus, the lens apparatus comprising a communication device configured to transmit, to an external device, information for light amount compensation of image data obtained by image pickup in the camera apparatus, in which the information includes information of a coefficient Aof a term of 0-th-order with respect to an image height in a polynomial of n-th-order with respect to the image height, and in which a conditional expression0.7&#x3c;()&#xd7;(())&#x3c;1.3is satisfied where A(Z) represents the coefficient Aat a zoom state Z, F(Z) represents an effective F-number at the zoom state Z, and Fw represents an effective F-number at a wide angle end.

Provided is a lens apparatus attachable and detachable to a camera apparatus including: a memory storing information for light amount compensation for image data obtained by pickup of an image formed by the lens apparatus; and a communication device configured to transmit the information to an external apparatus, the information including a coefficient of a polynomial having an n-th order with respect to an image height, 'n' being a non-negative integer, the coefficient corresponding to one of a plurality of focal lengths, the plurality of focal lengths including a focal length 'f', which satisfies a conditional expression: 0.9&#x3c;f/ft/(Fnw/Fnt)&#x3c;4, where Fnw represents an effective f-number at a wide angle end, Fnt represents an effective f-number at a telephoto end, and &#x201c;ft&#x201d; represents a focal length at the telephoto end.

Provided is a converter lens arranged between an interchangeable lens and an image pickup apparatus, wherein a distance from a most-object-side lens surface vertex to an object point of the converter lens, a distance L from the most-object-side lens surface vertex to a most-image-side lens surface vertex, and a most-image-side distance from the lens surface vertex to an image point of the converter lens are properly set, wherein, at least one negative lens included in a rear lens unit composed of lenses satisfying LN&#x3e;0.5&#xd7;L where LN is a most-object-side distance from the lens surface vertex to a surface vertex on the object side of the lenses, satisfies &#x398;gF&#x3e;&#x2212;0.00162&#xd7;vd+0.654, where &#x3b8;gF is relative partial dispersion and vd is Abbe number in d-line, and an average focal length of the at least one negative lens, and a focal length of an entire system of the converter lens are properly set.

Converter lens and camera apparatus including the same

A zoom lens includes, in order from an object side to an image side: a focus lens unit configured to be moved for focusing on an optical axis; a zoom lens unit configured to be moved for zooming on the optical axis; and a relay lens unit, in which an interval between each pair of adjacent lens units is changed for zooming, and the zoom lens includes an aperture stop arranged between the zoom lens unit and the relay lens unit or within the relay lens unit, the relay lens unit includes an extender lens unit insertable into and removable from an optical path of the relay lens unit, in which the extender lens unit includes a negative lens Lm which is an m-th lens from the object side in the extender lens unit and having a refractive index and an Abbe number that satisfy predetermined conditions.

Zoom lens, image pickup apparatus, and extender lens unit

A zoom lens includes a positive first unit, a negative second unit, and a rear lens system. The rear lens system includes a positive unit A, a negative unit B, and a positive C. The first unit is not moved for zooming, the unit A is moved for zooming, and intervals between adjacent lens units are changed during zooming. The first unit includes positive and negative lenses, the unit C includes positive and negative lenses, the second unit includes negative lenses, and the unit B includes positive lenses. An Abbe number average value of the positive lenses in the first unit, an Abbe number average value of the negative lenses in the second unit, an Abbe number average value of the positive lenses in the unit B, and an Abbe number average value of the positive lenses in the unit C are appropriately set.

Growing community of inventors

Yokohama, Japan

Koichi Sakuma