Lens control apparatus, imaging apparatus including lens control apparatus, and lens control method

A lens control apparatus, comprising:

• a control unit configured to control a position of a zoom lens and a position of a focus lens;
• a storage unit configured to store a plurality of tracks indicating a relationship between the position of the zoom lens and the position of the focus lens when each of a plurality of object distances is in focus;
• an object distance acquisition unit configured to acquire an object distance before movement of the zoom lens based on (a) a first track, (b) the position of the zoom lens and (c) the position of the focus lens before movement of the zoom lens;
• a target position acquisition unit configured to acquire a target position of the focus lens after movement of the zoom lens based on (d) a second track and (e) the position of the zoom lens after movement of the zoom lens, the object distance corresponding to the second track being different from the object distance corresponding to the first track, wherein the target position acquisition unit is configured to acquire the target position of the focus lens in either of (1) a first mode in which the target position of the focus lens is acquired so as to move a focal position based on the movement of the zoom lens and (2) a second mode in which the target position of the focus lens is acquired based on a result of focus detection performed based on an image signal acquired by photoelectrically converting light entering through the imaging optical system including the zoom lens and the focus lens;
• and
• a reliability acquisition unit configured to acquire a reliability of the focus detection,
• wherein the target position acquisition unit is configured to acquire the target position of the focus lens in (1) the first mode in a case where the reliability is lower than or equal to a threshold and acquires the target position of the focus lens in (2) the second mode in a case where the reliability is higher than the threshold,
• wherein the control unit is configured to control the position of the focus lens to the target position,
• wherein the target position acquisition unit is configured to determine the second track by estimating the object distance after the movement of the zoom lens based on (i) the object distance before the movement of the zoom lens acquired by the object distance acquisition unit and (ii) a ratio of a focal length before and after the movement of the zoom lens.