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Chapter 2. Geometrical optics
The aberration represented by the term proportional to D in
(2.216, 2.217) represents curvature of field. This aberration results
in an axial displacement of the plane of best focus which is proportional to the square of the radial distance off axis. The aberration
figure for curvature of field is plotted in Figure 2.10. The figure
Figure 2.10: Curvature of field.
schematically depicts a longitudinal section through the optical
system. The solid curved rays represent an object point on axis,
for which the image plane z I coincides with the Gaussian image
plane. The broken curved rays represent the aberrated rays for an
object point off axis, for which the plane of best focus lies on the
curve S. The focal surface for off-axis object points can be generated in three dimensions by rotating the curve labeled S about
the central optic axis. This surface therefore has axial symmetry.
The aberrations represented by the terms proportional to E and e
in (2.216, 2.217) represent isotropic distortion and anisotropic distortion, respectively. The aberration figures for positive and negative isotropic distortion are plotted in Figure 2.11. Isotropic distortion results in a radial displacement of the image point by an
amount which is proportional to the cube of the radial distance off
axis. The aberration figures for positive and negative anisotropic
Chapter 2. Geometrical optics
The aberration represented by the term proportional to D in
(2.216, 2.217) represents curvature of field. This aberration results
in an axial displacement of the plane of best focus which is proportional to the square of the radial distance off axis. The aberration
figure for curvature of field is plotted in Figure 2.10. The figure
Figure 2.10: Curvature of field.
schematically depicts a longitudinal section through the optical
system. The solid curved rays represent an object point on axis,
for which the image plane z I coincides with the Gaussian image
plane. The broken curved rays represent the aberrated rays for an
object point off axis, for which the plane of best focus lies on the
curve S. The focal surface for off-axis object points can be generated in three dimensions by rotating the curve labeled S about
the central optic axis. This surface therefore has axial symmetry.
The aberrations represented by the terms proportional to E and e
in (2.216, 2.217) represent isotropic distortion and anisotropic distortion, respectively. The aberration figures for positive and negative isotropic distortion are plotted in Figure 2.11. Isotropic distortion results in a radial displacement of the image point by an
amount which is proportional to the cube of the radial distance off
axis. The aberration figures for positive and negative anisotropic