1. An array camera system, comprising: an array camera comprising a plurality of cameras and a separate camera, where: the plurality of cameras capture images of a scene from different viewpoints; the separate camera has a fixed geometric relationship with each of the plurality of cameras in the array camera; and the separate camera captures an image of the scene from a different viewpoint to the viewpoints of the other cameras in the array camera; a processor; and memory in communication with the processor storing software; wherein the software directs the processor to: obtain a focus window based upon image data from the separate camera, where: at least one object is detected within an image captured by the separate camera; and the focus window is a defined region having a set of pixels, where the defined region is within an image captured by the separate camera based upon the location of the at least one object; determine a focus window for the array camera based upon the focus window from the separate camera, where the focus window for the array camera comprises a corresponding set of pixels that corresponds to the set of pixels within the focus window from the separate camera; obtain image data pertaining to the focus window of the array camera from at least two cameras in the plurality of cameras, determine depth information for the focus window of the array camera from the image data from the at least two cameras, colocate the depth information from the focus window of the array camera to the focus window of the separate camera to account for parallax between the separate camera and the plurality of cameras to generate depth information for the focus window of the separate camera, determine a focus depth for the separate camera based upon the depth information for the focus window of the separate camera, and adjust the focus of the separate camera to a desired focus based upon the determined focus depth for the separate camera.