Abstract: Sensitivity and resolution of an automated inspection system are improved and data processing loads for defect detection are reduced, increasing inspection speed, by fully illuminating an area corresponding to a nominal feature shape formed on a surface. Scanning of the illuminated area thus provides resolution of defects far smaller than the area of the illuminated spot. A preferred application of this automated inspection system is for the high speed screening of lamina or substrates having a pattern of through-holes formed therein, particularly for the formation of via connections therein. Screening for insufficient clear area of through-holes is done simply by applying a threshold to the output representing the amount of illumination transmitted and preferably reflected through the through-hole.