SCALES AND DISTORTION-CONSTANTS OF 4 SOUTHERN TELESCOPES

Scales and distortion constants have been derived for the CTIO 4-m and 1.5-m and Las Campanas 2.5-m and 1-m telescopes with their correctors. The CTIO 4 m, as expected, is very similar to its KPNO counterpart, though the central scale (but not the distortion) at CTIO is slightly different from KPNO. At both 4-m telescopes the distortion is slightly color dependent. The three smaller telescopes have much less, but still significant, distortion at their f/7.5 Ritchey-Chretien foci. Ray tracing of the published parameters of the Las Campanas telescopes with comparison to measures of plates from these telescopes shows that the published data apparently do not accurately describe the real telescopes. Some aspects of the problem of deriving positions for multiobject spectroscopy are discussed.