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+++++
Current tube temperature is 0.0
800 107,106:26706.00, Cent=107.29:106.18 Fwhm=7.63 Mag=8.54 Sky=6154.02 fom= 0.6960, 0.0 0,0
850 105,107:53267.00, Cent=105.50:107.05 Fwhm=6.71 Mag=7.89 Sky=2722.31 fom= 0.7629, 0.0 0,0
900 106,107:51107.00, Cent=106.55:107.25 Fwhm=7.10 Mag=7.89 Sky=2900.38 fom= 0.7319, 0.0 0,0
950 107,107:65535.00, Cent=107.71:107.63 Fwhm=6.06 Mag=7.84 Sky=3658.44 fom= 0.8963, 0.0 0,0
1000 109,107:65535.00, Cent=109.20:107.28 Fwhm=6.12 Mag=7.69 Sky=3329.07 fom= 0.7807, 0.0 0,0
1050 109,108:64520.00, Cent=108.87:108.06 Fwhm=6.42 Mag=7.76 Sky=3366.52 fom= 0.8198, 0.0 0,0
1100 109,107:56617.00, Cent=108.94:107.48 Fwhm=6.74 Mag=7.85 Sky=2805.64 fom= 0.7815, 0.0 0,0
1150 111,109:36011.00, Cent=110.59:108.80 Fwhm=8.08 Mag=8.09 Sky=4776.80 fom= 0.6201, 0.0 0,0
1200 108,106:25680.00, Cent=108.85:106.57 Fwhm=8.14 Mag=8.97 Sky=7243.37 fom= 0.9945, 0.0 0,0
2013/03/27 04:18:45
Best focus at 950 fwhm = 6.06 tube temp 0.0
Parabolic fit to fwhm data: X= focpos - (1000)
Parabolic Fit constants 4.3207792207792206e-5X**2 + 0.00193X + 6.27987012987013
best focus 977.6660655244965 from parabolic fit
Best focus at 1200 fom = 0.99448 tube temp 0.0
Parabolic fit to fom data: X= focpos - (1000)
Parabolic Fit constants 5.138961038961946e-8X**2 + 0.00026268333333333315X + 0.786220173160173
best focus out of range from parabolic fit
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PROCEDURE
The TCL code to run inplace_focus is loaded, after startup and initialization of LOIS by
- using the SrcLMITools user button.
- in the command editor in the LMI LOUI, type source expertools/focus.tcl
This is provisional and will be made more automatic later.
A star is acquired and a full frame test single (binned 2:2 on LMI) taken. The star is moved to the center as needed, and an exposure time suitable to provide good input to the focus sweep is estimated. This needs to be long enough to provide adequate counts at each end of the range. The focbase is selected as a focus setting not too distant from the actual correct value. The step size is usually already known as a function of the instrument. It is usually best to use the full 10 steps in the sweep as provided by default.
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