In this aberration, rays from an off-axis point encounter a lens that is tilted, resulting in asymmetry about the lens axis and different focal lengths for rays with different orientations.
In this aberration, rays from an off-axis point encounter a lens that is tilted, resulting in asymmetry about the lens axis and different focal lengths for rays with different orientations. At the inside and outside focal points, a point source is imaged as a line parallel to the weakest and strongest principal planes, respectively.
In this aberration, rays from an off-axis point encounter a lens that is tilted, resulting in asymmetry about the lens axis and different focal lengths for rays with different orientations.
Astigmatism