Phase detection autofocus using subaperture images

A light-field camera may have enhanced autofocus functionality that does not require a dedicated optical pathway or dedicated sensors, and yet brings the camera rapidly into focus for image capture. According to one method, light may be received through the aperture of a light-field camera, with the main lens of the light-field camera at a first focus setting. The light may be directed to a sensor of the light-field camera via an optical pathway. The sensor may capture the light to generate preliminary light-field data. In a processor, the preliminary light-field data may be used to generate an offset, which may be used to refocus the main lens to a second focus setting. Additional light may be directed along the same optical pathway and captured with the main lens at the second focus setting to capture a focused light-field image.