L. Gutierrez et al., DETECTION AND CORRECTION OF SCATTERED-LIGHT IN THE 2.1-M SAN-PEDRO MARTIR TELESCOPE, Revista Mexicana de Astronomia y Astrofisica, 32(2), 1996, pp. 63-67
We have used the pinhole camera method (Grundhal & Sorensen 1966) to e
valuate the amount of scattered light present at the exit pupil of the
f/7.5, 2.1-m San Pedro Martir telescope. A substantial amount of scat
tered light, originating from multiple reflections off the inner walls
of the sky baffles was found to be present; this scattered component
directly affects the quality of the flat-field calibration frames, whi
ch is in turn reflected on the accuracy of CCD bidimensional photometr
y. Corrective action has been performed on the primary's sky baffle, s
uccessfully eliminating most of the spurious scatterea component.