A lens system for a camera, comprising: an image formation optical system including a movable lens group, a first correction lens group (12, 14) whose position relative to an optical axis is changeable so that optical performance of each portion of an image is corrected and a second correction lens group, whose position is changeable in a plane perpendicular to the optical axis so that a position of an image center is adjusted; the first correction lens group (12, 14) comprises a decentering correction lens group and the tilt correction lens group, wherein the decentering correction lens group is arranged to move in a plane perpendicular to the optical axis direction and the tilt correction lens group is arranged to rotate about an axis set forth in a direction perpendicular to the optical axis direction so that the tilt angle varies while the tilt correction lens group moves in parallel to the optical axis direction; and the second correction lens group comprises a camera-shake correction lens group provided in a manner of being movable in a plane perpendicular to the optical axis of the optical system; wherein a drive section is adapted to drive the first correction lens group (12, 14) and the second correction lens group; a lens position acquisition section is adapted to acquire a lens position of the movable lens group; a specification section is adapted to specify a partial image of a part of region in the image; a storage section is adapted to store a data table in which correspondence is established between position information of both of the movable lens group and the first correction lens group (12, 14) and the optical performance of each portion of the image; and a control section is adapted to, in accordance with the lens position of the movable lens group acquired by the lens position acquisition section, on the basis of the data table, acquire a position for the first correction lens group (12, 14) that improves the optical performance of the partial image specified by the specification section and then to control the drive section such as to move the first correction lens group (12, 14) to the acquired position, and to move the second correction lens group for correcting displacement of the image center caused by the movements of the first correction lens group (12, 14) and the movable lens group on the basis of the position information of the first correction lens group (12, 14). an image formation optical system including a movable lens group, a first correction lens group (12, 14) whose position relative to an optical axis is changeable so that optical performance of each portion of an image is corrected and a second correction lens group, whose position is changeable in a plane perpendicular to the optical axis so that a position of an image center is adjusted; the first correction lens group (12, 14) comprises a decentering correction lens group and the tilt correction lens group, wherein the decentering correction lens group is arranged to move in a plane perpendicular to the optical axis direction and the tilt correction lens group is arranged to rotate about an axis set forth in a direction perpendicular to the optical axis direction so that the tilt angle varies while the tilt correction lens group moves in parallel to the optical axis direction; and the second correction lens group comprises a camera-shake correction lens group provided in a manner of being movable in a plane perpendicular to the optical axis of the optical system; wherein a drive section is adapted to drive the first correction lens group (12, 14) and the second correction lens group; a lens position acquisition section is adapted to acquire a lens position of the movable lens group; a specification section is adapted to specify a partial image of a part of region in the image; a storage section is adapted to store a data table in which correspondence is established between position information of both of the movable lens group and the first correction lens group (12, 14) and the optical performance of each portion of the image; and a control section is adapted to, in accordance with the lens position of the movable lens group acquired by the lens position acquisition section, on the basis of the data table, acquire a position for the first correction lens group (12, 14) that improves the optical performance of the partial image specified by the specification section and then to control the drive section such as to move the first correction lens group (12, 14) to the acquired position, and to move the second correction lens group for correcting displacement of the image center caused by the movements of the first correction lens group (12, 14) and the movable lens group on the basis of the position information of the first correction lens group (12, 14).