Palomar 200-inch Telescope:

LFC - Large Format Camera

Camera Parameters

Mosaic of six 2048 x 4096 pixel SITe SI-002 thinned, backside illuminated, AR coated CCD located at Hale Telescope's Prime Focus (f/3.3)
Field Diameter: 24 arcminutes
Pixel size: 15 microns
Pixel Scale:
- 0.18"/pixel binned 1x1
- 0.36"/pixel binned 2x2
Minimum Exposure time: 0.6 sec
Gap between CCD chips: ~ 15 arcsec
Readout (Mosaic) Options:

Mode (mosaic command)	Chip Numbers Used	Binning Value (pixels)	Field Size (arcmin)	Readout Time (sec)
lfc / lfc2 lfc2bin lfcfour lfczero lfczerobin lfcfind	0, 1, 2, 3, 4, 5 0, 1, 2, 3, 4, 5 0, 1, 2, 3 (center 4) chip 0 only chip 0 only chip 0 only	1 x 1 2 x 2 1 x 1 1 x 1 2 x 2 2 x 2	25.3' x 24.8' 25.3' x 24.8' 12.5' x 24.8' 6' x 12.3' 6' x 12.3' 6' x 6'(1k x 1k)	115 56 111 105 45 31

Image File Size: ~ 17 Mb per CCD at 1 x 1 binning
LFC Guider: partially vignetted 512 x 512 SITe chip located in the open area between chips 3 and 5. See focal plane schematic. Capable of guiding down to mV ~ 18

CCD Specs

2048 x 4096 pixel SITe SI-002 thinned, backside illuminated, AR coated CCD

CCD Chip #	Bias	Gain (e^-/DN)	Read Noise (e^-)	Saturation (DN)
0	650	2	11	59100
1	1700	1.9	9	53400
2	1100	2.1	9	40800
3	2600	2	8	44000
4	1700	2.1	8	21700
5	4100	1.8	6	61400

LFC Filter Specs

Filter wheel has slots for 4 filters

Filter	Central (A)	Width (A)	Thickness (mm)	Focus Offset (mm from r')	Domeflats *	Transmission Text File
r'	6255	1470	3.05	-	5	r'.txt
i'	7680	1540	3.05	-	3	i'.txt
z'	~9000	~1800 (w/qe)	3.05	-	5	z'.txt
g'	4660	1400	8.02	+1.5	40	g'.txt
u'	3540	590	8.38	+1.6	120 (HIGHLAMP)	u'.txt
Rs	6930	1220	10.26	+2.0	3	Rs.txt
Is	8190	1670	10.26	+2.0	3	Is.txt
B-bess	4400	1000	7.0	+1.3	3	B.txt
V-bess	5500	900	7.0	+1.3	3	V.txt
R-bess	6300	1200	7.0	+1.3	3	R.txt
I-bess	9000	3000	7.0	+1.3	3	I.txt
Broad-RI	7670	2940	6.0			RI.txt
H-alpha	6570	100	11.68	+2.6		see plots below
S-II	6730	90	11.68	+2.7		see plots below

Figure:

Rs transmission curve

Is transmission curve

New (Nov. 2007) Narrow Band Filters, Courtesy of Karl Stapelfeldt.

H-alpha transmission curve

S-II transmission curve

Custom LFC Filters

6.1 inches square
Thickness: ~3 mm (min); 10 mm (max), but < 6 mm preferred due to weight considerations.
Contact: Jeff Hickey about non-observatory filter mounting. Also see Rob Simcoe's LFC Page for more information.

Latest LFC News

MCDCOM Program Update (February 20, 2007):
- Added logic to filter wheel movement so that the filter wheel will correctly move to the requested position in both extreme cold and extreme hot ambient temperatures.
- Created two new backup MCDCOM programs in case the hot/cold logic fails:
  - mcdcom_hot to be used in hot temperatures
  - mcdcom_cold to be used in cold temperatures
- When mcdcom is started, 3 scripts are automatically copied to the user's working directory (if none exist):
  - focus_coarse
  - focus_fine
  - dither5
- A test version of the lfcguider (lfcguide_ns) is now available which attempts to guide at non- sidereal rates. Target rates are entered in the File/BlackBelt menu popup window
MCDCOM Program Update (April 28, 2005):
- The iraf command now works. When toggled ON, files are written as signed integer FITS.
- The istat command now works correctly, displaying the mean of chip 0.
- A new command fs has been added. This adds a filename suffix (eg: .fits). To clear this at any time, issue fs "".
- New commands have been added to turn lamps on and off from the command line, useful in domeflat scripts:
  - telescope lowlamp
  - telescope highlamp
  - telescope arclamp
  - telescope lampsoff
- Fixed the header bug in the guider program. All fits files should now have proper telescope header information, regardless of when a "go" is issued.
Added Narrow Band Filters (Nov. 2007)
- Karl Stapelfeldt has supplied two new Narrow Band filters from Asahi Spectra. The filter plots are linked above, and are named H-alpha and S-II.

Contact: Jeff Hickey
Last modified: Jan. 30, 2008

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