Yu.V. Bazhanov, V.B. Vlahko
Existing off-axial optical systems aberration theories are based on series expansion of optical path function (eikonal function). Numerical evaluations, conducted in this paper, have shown, that the most accurate results are obtained with theory, based on series expansion of exact ray-tracing equations, where expressions for high-order aberration coefficients include expressions for low order ones. We have used that very method in our search of optimal decision for off-axis optical reflective telescope systems.