Anastigmatic cassegrain type telescope.
The 152-cm telescope of the Cerro Tololo Inter-American Observatory in Chile is to be made to a design producing images that are free of the usual Ritchey-Chrétien astigmatism. A 38-cm diam fused-quartz correcting plate is used to give a field diameter of 1. degrees 5, over which images are less than 0.5 see of arc in diameter.
Schulte
D H
DH
Itek Corporation, Lexington, Massachusetts, USA.