ABSTRACT
In a lens design or ray tracing program, the transverse aberrations are more easily obtained and analyzed than the wavefront aberrations. Ray tracing is performed with most lens evaluation or ray tracing programs. The ray paths from a point object in the object plane and for several heights along the y axis are traced toward the entrance pupil. In a more quantitative manner, one can calculate the values of the transverse aberration at several points and then we can make a polynomial fit to find the coefficients. In the primary and fifth-order astigmatism, also called linear astigmatism, the Seidel component is the primary astigmatism at the Petzval surface with the proper defocusing to shift the image to the Gaussian image plane. For primary and fifth-order distortion aberrations, the tangential plots are just moved in the y direction. This is equivalent to a shift off-axis of the image.
