A systematic design study on telecentric large aperture lenses

The Double-Gauss (Planar) design is widely adopted when fast apertures such as f/2 or lower are needed for photographic and digital imaging applications. In this study, we examine the effects of imposing an image-side telecentricity constraint on this design type. We also trace the evolution of the Double-Gauss layout toward the Distagon configuration as larger apertures become desirable. Drawing on Glatzel’s research on microlithographic objectives, we explain this design transition leading to Distagon structures. We place special emphasis on field curvature, which emerges as the most challenging aberration to correct as apertures approach f/1 and below. Finally, we present a sequence of optical layouts for an unvignetted 50 mm focal length lens system operating in the visible waveband as the aperture expands from approximately f/3 to f/0.9. This demonstrates the growth in the system’s mechanical envelope that accompanies this expansion.