1. A method for operating a precision machine vision inspection system to interdependently determine lighting parameters and a refined precise focus Z-height corresponding to a precise image focus for a first focus region of interest on a workpiece, the precision machine vision inspection system including an imaging portion, a controllable lighting portion, a focusing portion, and a control portion comprising an image processor, the method comprising: (a) illuminating the first focus region of interest on the workpiece with the controllable lighting portion controlled by an initial set of light control parameters; (b) operating the precision machine vision inspection system to provide an initial set of focus curve data for the first focus region of interest, based on an initial set of workpiece images acquired using the initial set of light control parameters at a plurality of Z-heights; (c) quantitatively estimating an initial focus Z-height based on the initial set of focus curve data for the first focus region of interest; (d) setting the precision machine vision inspection system at the initial focus Z-height for the first focus region of interest; (e) automatically determining a set of refined light control parameters based on at least one respective image of the first focus region of interest acquired using respective light control parameters at the initial focus Z-height, wherein the set of refined light control parameters are determined such that they correspond to an image having a value for at least one contrast-related metric that is indicative that the set of refined light control parameters will provide a set of focus curve data that has a higher peak value than a peak value of the initial set of focus curve data; and (f) performing at least one of the sets of operations (f1) and (f2), wherein (f1) comprises: (f1) storing the set of refined light control parameters in association with a part program for later use when inspecting a corresponding first focus region of interest on a corresponding workpiece, and (f2) comprises: (f2) operating the precision machine vision inspection system to provide a refined set of focus curve data for the first focus region of interest, based on a set of refined workpiece images acquired using the set of refined light control parameters, and estimating the refined precise focus Z-height for the first focus region of interest, wherein the refined precise focus Z-height is quantitatively estimated based on the refined set of focus curve data.