(1) It is thus an object of this invention to provide a three mirror anastigmatic optical system employing conic mirrors wherein the system is off-axis in both aperture and field angle.(2) Important special cases of stationary anastigmatic mounts and their performance are presented.(3) By increasing 2, as compared to the anastigmatic design, the coma can be cancelled completely.(4) A table of parameters for anastigmatic lenses is included.(5) Devices that reduce technical difficulty and anastigmatic time when repairing large vessels such as the thoracic aorta would be beneficial.
