title: Third-order design of refractive Offner compensators.
abstract: From first-order optics and the condition for zero third-order spherical aberration, a simple set of equations can be derived to produce a good preliminary design of a refractive Offner compensator. An advantage of these formulas is that they provide a design that satisfies specified values for the diameter of the compensating lens and the focal ratio of the cone of observation. An example is given to show how the formulas are used.
authors.forename: J R
authors.initials: JR
authors.lastname: Moya
authors.forename: J E
authors.initials: JE
authors.lastname: Landgrave