The relations between the axial aberrations of photographic lenses and their optical transfer functions.

The wave aberration of a photographic lens can be represented for an axial image point by means of three coefficients. The usual values of these coefficients are studied. The optical transfer function (OTF) is computed from the wave aberration by means of an analog computer and represented as a function of the size and the shape of the wave aberration. The influence of stopping down the aperture on the image quality is investigated.