Zeiss CFE Distagon f/4 40 mm FLE
Overview
Technology often glossed over, the "FLE" — floating lens element designation indicates that the photographer can tune controls to correct for converging or diverging line distortion.
This Zeiss approach distortion control correction should not be confused with Minolta's or Nikon's architectural lens application approaches It offers a fine tweaking adjustment to apparent pincushion/barrel distortion. Nikon's approach has been, traditionally, to produce a much larger than format coverage, extremely flat field, low distortion lens and offset it keeping the subject and image planes parallel. The more versatile Minolta approach had been to vary the curvature of the focal plane with an internal floating group to best optimize non convergence or divergence of image parallel straight lines.
This lens would typically be employed in architectural photography at a variety of distances.
