Compound reflective optical systems including Cassegrain, Ritchey-Chretien, Dall-Kirkham and various modifications. Refractive systems including achromatic and apochromatic objectives and full aperture corrector catadioptric systems including Schmidt, Maksutov and Houghton types along with near focal corrector systems. Also produces off-axis mirrors.
R.F. Royce - Precision Optical Components