Various embodiments disclosed herein include techniques for operating a multiple camera system. In some embodiments, a primary camera may be selected from a plurality of cameras using object distance estimates, distance error information, and minimum object distances for some or all of the plurality of cameras. In other embodiments, a camera may be configured to use defocus information to obtain an object distance estimate to a target object closer than a minimum object distance of the camera. This object distance estimate may be used to assist in focusing another camera of the multi-camera system.