1. An image capturing apparatus comprising: an image capturing unit adapted to capture an image of an object and sequentially acquire image data associated with the image capturing; a storage unit adapted to store model data associated with a first feature quantity calculated from a feature point of the object in a model image; a calculation unit adapted to calculate a second feature quantity from a feature point of the object in each of the sequentially acquired image data; a prediction unit adapted to predict, on the basis of (a) a transition of the second feature quantity and (b) the first feature quantity, a timing when a difference between the first feature quantity and the second feature quantity will satisfy a predetermined condition; and a control unit adapted to store the image data acquired at the predicted timing in an image data storage unit.