It has recently been suggested that a concentric corrector, i.e., a corrector all the surfaces of which are normal to axial rays in the paraxial region, might be used to correct field curvature alone. The theory given was not sufficiently extended to show what errors the corrector will introduce. In particular, it does affect distortion in the extended paraxial region. Further, when the corrector is placed somewhere within the system its effects on the contributions to the aberrations by those surfaces of the original system which follow the corrector must be taken into account, and these effects may in particular cases be substantial. This paper therefore provides a careful and detailed analysis of the problem under consideration, and the theory follows closely that of concentric systems developed in an earlier paper of the present series. Numerical illustrations are provided.
H. A. BUCHDAHL, "Optical Aberration Coefficients. XI. Theory of a Concentric Corrector," J. Opt. Soc. Am. 52, 1367-1371 (1962)