Provided is an image-acquisition apparatus including an image-acquisition lens that collects light coming from a subject A; an image-acquisition device that acquires images with the light collected by the image-acquisition lens; a microlens array that is disposed between the image-acquisition device and the image-acquisition lens; and a distance calculating portion that calculates a distance to the subject by using information obtained by the image-acquisition device. The microlens array has multiple types of microlenses, for different polarization states, that focus light incident thereon to form individual images on an image-acquisition surface of the image-acquisition device and that are arranged in an array in directions orthogonal to an optical axis thereof, and the distance calculating portion calculates the distance by performing matching processing in which each polarization state is weighted according to frequency components of the information obtained by the image-acquisition device.