 Coma aberration

Online text: www.telescope-optics.net/coma.htm

Cited passages: Amateur Telescope Optics, §4.2, Figure 41: geometrical spots versus diffraction images; Amateur Telescope Optics, §4.2, classical coma formula after equation 15 and equation 13: pupil-cubic and field-linear dependence; Amateur Telescope Optics, §4.2, opening paragraphs and Figure 39: field coma versus misalignment coma.