4.0-m R-C Spectrograph Quick Reference

Plate Scale (at f/7.8 focal plane) 6.56 arcsec/mm
Slit Length 50 mm
328 arcsec
Collimator Focal Length 1161 mm
Point source collimated beam diameter 152 mm
Collimator-to-Camera Angle 46°
Grating size 203×254 mm
Camera Focal Length 229 mm
Demagnification 5.070
Plate Scale (at detector) 33.3 arcsec/mm
  • At f/7.8 focus, 1 arcsecond = 152 micron
  • With the Loral 3K CCD:
    • The spatial scale on the detector is 0.50 arcsec / 15 micron pixel.
    • For anamorphic demagnification of 1.0, the 2-pixel projected slit is 1.0 arcsec or 152 micron wide.
    • The full slit length illuminates ~657 rows.

 

Michael Keane (mkeaneATnoao.edu)
Jack Baldwin (jbaldwinATnoao.edu)