An apparatus comprising: a microscope objective focused on a microscope field of view ; a light source including a laser generating an astigmatic beam having astigmatism tan(β)/tan(α) where β is largest divergence angle of the astigmatic beam and α is the smallest divergence angle of the astigmatic beam and having an aspect ratio of tan(β):tan(α), and optics configured to couple the astigmatic beam into the microscope objective to produce high aspect ratio illumination at the microscope field of view , the optics comprising an aspherical lens arranged to compensate the astigmatism of the astigmatic beam but not the aspect ratio; and a data acquisition system configured to generate data pertaining to light emanating from the microscope field of view responsive to the high aspect ratio illumination ; characterized in that the aspherical lens has different foci in the orthogonal directions, a finite focal length in the direction of the largest beam divergence angle β effective to collimate light with the largest beam divergence angle β and has a finite focal length in the direction of the smallest beam divergence angle α effective to collimate light with the smallest beam divergence angle α to convert the astigmatic beam to an astigmatism-corrected collimated beam having an aspect ratio of tan(β):tan(α) and the microscope objective images the astigmatism-corrected collimated beam at the microscope field of view to produce the high aspect ratio illumination at the microscope field of view , wherein the high aspect ratio illumination at the microscope field of view has an aspect ratio of tan(β):tan(α). a microscope objective focused on a microscope field of view ; a light source including a laser generating an astigmatic beam having astigmatism tan(β)/tan(α) where β is largest divergence angle of the astigmatic beam and α is the smallest divergence angle of the astigmatic beam and having an aspect ratio of tan(β):tan(α), and optics configured to couple the astigmatic beam into the microscope objective to produce high aspect ratio illumination at the microscope field of view , the optics comprising an aspherical lens arranged to compensate the astigmatism of the astigmatic beam but not the aspect ratio; and a laser generating an astigmatic beam having astigmatism tan(β)/tan(α) where β is largest divergence angle of the astigmatic beam and α is the smallest divergence angle of the astigmatic beam and having an aspect ratio of tan(β):tan(α), and optics configured to couple the astigmatic beam into the microscope objective to produce high aspect ratio illumination at the microscope field of view , the optics comprising an aspherical lens arranged to compensate the astigmatism of the astigmatic beam but not the aspect ratio; and a data acquisition system configured to generate data pertaining to light emanating from the microscope field of view responsive to the high aspect ratio illumination ; characterized in that the aspherical lens has different foci in the orthogonal directions, a finite focal length in the direction of the largest beam divergence angle β effective to collimate light with the largest beam divergence angle β and has a finite focal length in the direction of the smallest beam divergence angle α effective to collimate light with the smallest beam divergence angle α to convert the astigmatic beam to an astigmatism-corrected collimated beam having an aspect ratio of tan(β):tan(α) and the microscope objective images the astigmatism-corrected collimated beam at the microscope field of view to produce the high aspect ratio illumination at the microscope field of view , wherein the high aspect ratio illumination at the microscope field of view has an aspect ratio of tan(β):tan(α). <EOS>