Improved Coude Efficiency of Existing Telescopes

The ordinary coude train has a single, large, aluminum coated mirror at each reflection point. This introduces considerable light loss because several reflections are required, and the long light path in turbulent air blurs the stellar image by telescope “seeing” effects. The transmission can be increased and the blur decreased by a train of small mirrors with high reflectance coatings. The high reflectance coatings have the added advantages that they can reduce polarization effects and flatten response curves.