Investigation of the Influence of Apodization on the Sine Wave Response of Photographic Lenses

Abstract

To change the imaging characteristics of an optical system by apodization, one intervenes in the pupil function. This intervention can be aimed if one knows the system’s wavefront aberrations. Several intervention functions which are selected for desired apodization are given and the criteria, for their selection. The measuring apparatus is described. It partly originates from an array of Lamberts: sine wave tests are produced by imaging sinusoidal patterns by a cylinder lens. The preparation of appropriate sinusoidal patterns and apodization filters by new methods are outlined. Problems of adjustment are sketched, e.g., Fourier images. The results show improvement of the frequency response function (now called optical transfer function) of the optical system. Comparisons are made of pupils with the same diameter as well as of pupils with the same emerging radiant power.