1.5-m R-C Spectrograph Quick Reference

Plate Scale (at f/7.5 focal plane)	18.06 arcsec/mm
Slit Length	25.4 mm 459.7 arcsec
Collimator Focal Length	766.1 mm
Point source collimated beam diameter	101.6 mm
Collimator-to-Camera Angle	55°
Grating size	127×152 mm
Camera Focal Length	160 mm
Demagnification	4.788
Plate Scale (at detector)	86.7 arcsec/mm

At f/7.5 focus, 1 arcsecond = 55 µ
With the Loral 1K CCD:
- The spatial scale on the detector is 1.3 arcsec / 15 µ pixel.
- For anamorphic demagnification of 1.00, the 2-pixel projected slit is 2.6 arcsec or 144 µ wide.
- The full slit length illuminates ~357 rows.
NOTE: The best instrumental "seeing" you can expect is approx. 3.5 arcsec, or spatial FHWMs of approx. 2.7 pixels.

Knut Olsen: kolsen@noao.edu
Chris Smith: csmith@noao.edu