a circle and the left half of the mask had a radiant intensity which was the left half of a circle additionally the present invention makes possible the illumination of a desired area on a reticle or mask such as an arcuate rectangle or other shaped area the present invention also provides a desired irradiance distribution with a uniform irradiance distribution usually desired but may provide for a different profile or irradiance distribution if desired the present invention also provides an illuminated region that is effectively self luminous additionally each point in the illumination region is illuminated by the same desired angular spectrum whether it is uniform annular quadrupole or other desired distribution the present invention also provides that the exit pupil for each point in the illumination region is in the same location to prevent telecentricity errors the first non imaging optic element 14 collects electromagnetic radiation from the source 12 the combination of the first and second non imaging optic elements 14 and 18 forms the desired irradiance distribution at the illumination system 10 or condenser pupil and forms an image of the source 12 the second non imaging optic element 18 functioning as a beam shaper the beam shaper located at the pupil of the illumination system 10 or condenser scatters the incident radiation so that the image of the source fills the desired region of the reticle or mask 30 each point of the reticle or mask 30 receives light or electromagnetic radiation from a large number of discrete points in the pupil the discrete points may number in the millions depending upon the size of the facets 34 on the second non imaging optic.