Troubleshooting guide
Imaging Sensitivity
FWHM = 2 pixels (1.2 arcsec)
Aperture 2.8 arcsec diameter
Band
e/s for 
mag=15
sky 10 σ limiting magnitude
mag-arcsec
-2
e-sec
-1
-pixel
-1
60 seconds 600 seconds 3600 seconds
J 1050 15.1 335 17.6 18.8 19.8
H 1320 13.1 2815 16.7 17.9 18.9
K 1300 12.7 4028 16.5 17.7 18.7
Ks 1140 12.9 3925 16.3 17.6 18.6
These data are from the KPNO FLAMINGOS web site, http://www.kpno.noao.edu/manuals/flmn.  
The above data were for the original J, H, and Ks filters, which were on loan from NOAO and Gemini. New J, 
H, and Ks filters were installed during the summer of 2003. The signal levels with the new filters are similar to 
those in the table.
Decker, Filter, Lyot, and Grism Wheel Positions
DECKER
9000 STEPS
FILTER
1250 STEPS
LYOT
1250 STEPS
GRISM
1250 STEPS
 dark 0 J 0  Hartmann1 0  open1 0
 imaging 2250 H 208  Hartmann2 178  JH 250
 slit 4500 K 417  open 357  true-dark 500
 mos 6750 HK 625  gemini 536  open2 750
JH 833  mmt 714  HK 1000
Ks 1042  4m 893
 2.1m 1071
Note that the “true-dark” position in the Grism wheel is the only cold dark stop in the instrument and must  
be used for obtaining any dark frames.
When using the config.rel.mv.filter.grism.decker.wheels.pl script [Move Wheels], the positions will be split into 
positive and negative locations centered on the home position to minimize the motion time. Thus, the HK grism 
will have a location step = -250 in that script.
FLAMINGOS@2.1-m, Ver. 2.39, 2011 May 13 Page 7 of 46










