The second determining unit may determine the calculation area based on a positional relationship between the image stabilizing area and the focus detecting area. The first determining unit and the second determining unit may acquire object information based on an output signal from the image sensor 102. The focus detecting apparatus may have an image stabilizing unit (image stabilizing amount calculating unit 113, image sensor driving control unit 114) configured to perform image stabilization based on the image stabilizing area. The focus detecting apparatus further includes a calculating unit (image shift amount calculating unit 110) configured to calculate an image shift amount between image signals in the calculation area.

The object information may include information about at least one of a position (coordinates), size, reliability, and type of the object. In a case where the image stabilizing area is an entire image, the calculation area may be smaller than an object in the object information. The calculation area in a case where the image stabilizing area and the focus detecting area are the same (substantially the same) may be larger than that in a case where the image stabilizing area and the focus detecting area are different. The calculation area in a case where the focus detecting area is part of the image stabilizing area may be larger than that in a case where the image stabilizing area and the focus detecting area are different. The calculation area in a case where the image stabilizing area and the focus detecting area are related object types may be larger than that in a case where the image stabilizing area and the focus detecting area are not related object types.