1. A photography apparatus comprising: a selecting unit configured to select one of a plurality of photography modes, including a follow up photography mode; a tomographic image acquiring unit configured to acquire a plurality of polarization-sensitive tomographic images obtained by photographing an object at different times; and a positioning unit configured to, in a case where the follow up photography mode has been selected, position the plurality of polarization-sensitive tomographic images based on a plurality of polarization planar images of the object corresponding to the plurality of polarization-sensitive tomographic images.