1. In a machine vision inspection system, a method for focusing to provide an inspection image, the method comprising: during a run mode of the machine vision inspection system, automatically approximately focusing an inspection image using a set of operations comprising: acquiring a first image of a current region of interest including a feature to be inspected and determining a first image focus value in the current region of interest; accessing previously learned representative feature-specific focus curve data and focus threshold value data corresponding to the current region of interest; evaluating the first image focus value to determine if it is worse than the focus threshold value and, when the first image focus value is worse than the focus threshold value performing a subset of operations comprising: moving a focusing element that is one of (a) the feature to be inspected and (b) a focus determining optical element, along a primary adjustment direction for an estimated primary adjustment distance, wherein the primary adjustment distance is estimated based on the representative feature-specific focus curve data and the first image focus value; acquiring a second image of the current region of interest after moving the estimated primary adjustment distance, and determining a second image focus value in the region of interest in the second image; and evaluating the second image focus value to determine if it is worse than a previously determined focus value parameter and, when the second image focus value is worse than the previously determined focus value parameter, moving the focusing element along a secondary adjustment direction that is opposite to the primary adjustment direction for an estimated secondary adjustment distance that is an estimated distance to a best focus position based at least in part on one of (c) the primary adjustment distance and (d) the representative feature specific focus curve data.