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).