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 µ
With the Loral 3K CCD:
- The spatial scale on the detector is 0.50 arcsec / 15 µ pixel.
- For anamorphic demagnification of 1.0, the 2-pixel projected slit is 1.0 arcsec or 152 µ wide.
- The full slit length illuminates ~657 rows.
Michael Keane (mkeane@noao.edu)
Jack Baldwin (jbaldwin@noao.edu)