Submicron device fabrication entailing ringfield x-ray pattern delineation is facilitated by use of a condenser including a faceted collector lens. The collector lens is constituted of paired facets, symmetrically placed about an axis of a laser-pumped plasma source. Each of the members of a pair produce an image of the entire illumination field so that inhomogeneities in illumination intensity are compensated within each composite image as produced by a particular pair.