Spectroscopy is done with the Large Field Objective (pixel scale ~ 0.29 arc / second), one of three slits and one of three grisms.
Long Slits 
Slits  (arcsec) 2 x 290  
1 x 290 
0.6 x 290 
Table 1. SOFI slits. Grisms 
Grism \ Parameters Order 
Dispersion 
Resolution (0.6" slit) 
Wavelength Range 
GB Grism Blue 
1 
6.96 
1000 
0.95-1.64 
GR Grism Red 
1 
10.22 
1000 
1.53-2.52 
HR Grism 
3 
4.63 
2200 
2.00-2.30 
HR Grism 
4 
3.44 
1500 
1.49-1.81 
HR Grism 
5 
2.71 
1400 
1.20-1.28 
HR Grism 
6 
2.32 
1400 
1.17-1.24 
HR Grism 
7 
1.87 
1400 
0.89-0.93 
HR Grism 
8 
1.58 
1400 
0.86-0.95 
Table 2. SOFI Spectroscopy modes. Line Identification 
Reccomended DIT/NDIT for Arcs and Flats 
Arcs: DIT=5 sec, NDIT=10 (for both LR and MR) 
Flats: DIT=2 sec, NDIT=30 (for both LR and MR) 
 
Distortion maps for spectroscopy 
Calibration data  for distortion corrections, for all spectrosocpic modes (link to the new ftp site; last set of distortion calibrations from 2011-05-16).