
5.2.
Evaluation of Aberration Coefficients
75
Fig. 5.2. Location and orientation of astigmatic line images. Tangential and sagittal images are
denoted by T and S, respectively.
we use these results to evaluate the remaining coefficients in Eq. (5.1.6), which, if
non-zero, determine the magnitude and type of aberration present in an image.
5.2.
EVALUATION OF ABERRATION COEFFICIENTS
For an optical system that satisfies Eq. (5.1.7) for any {x,y) within the
aperture, each of the coefficients in Eq. (5.1.6) must be zero and the system is
perfect. If one or more of these coefficients is nonzero, then aberrations are
present. Not surprisingly, th