Signal Evaluation calibrating flats

dallyack

New member
Nov 11, 2021
3
0
All the tutorials I see including the one here on PI are using older versions. The ImageCalibration module in the examples do not show or mention the "Signal Evaluation" section. So my question is... Should I use Signal Evaluation when calibrating Flats? It seems it should be used for Lights based on how I interpret the pop-up tips.
 

Juan Conejero

PixInsight Staff
Sep 2, 2004
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Because signal evaluation is enabled when you calibrate flats. Signal and noise evaluation should only be enabled in the ImageCalibration process when calibrating non-CFA light frames. For CFA mosaiced light frames, both options should be enabled in the Debayer process.
 

Jkcolli

Active member
Aug 15, 2018
29
1
Juan
Since signal and noise evaluation should only be enabled in the ImageCalibration process when calibrating non-CFA light frames, would it make sense to uncheck and gray out Signal Evaluation and Noise Evaluation when Enable CFA is checked in ImageCalibration?

Jack
 

Juan Conejero

PixInsight Staff
Sep 2, 2004
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467
57
Valencia, Spain
pixinsight.com
Hi Jack,

ImageCalibration is able to perform signal evaluation for CFA frames if you enable the corresponding option (or leave it with its default enabled state). So there is no reason to disable this option when Enable CFA is checked. The main difference is that Debayer can compute separate per-channel signal estimates, while IC can only generate a single estimate for the whole frame.

Note also that the 'Enable CFA' option of ImageCalibration is only used for dark frame optimization and separate flat scaling factors (when that option is also selected). CFA raw frames are calibrated exactly the same way as non-CFA frames.