PixInsight Forum

PixInsight => General => Topic started by: GeneralT001 on 2018 October 18 21:36:19

Title: SubFrameSelector Warning (No Convergence)
Post by: GeneralT001 on 2018 October 18 21:36:19
I tried running the SubFrameSelector script and this warning showed up for each frame in the Process Panel. Also everything was "0" in the plots. What is it telling me and how do I fix it?

** Warning: No convergence in MRS noise evaluation routine: using k-sigma noise estimate
3.231 s
Title: Re: SubFrameSelector Warning (No Convergence)
Post by: GeneralT001 on 2018 October 18 21:50:40
It seems that I did not have "Optimize" and "Calibrate" selected when I ran the Image Calibration process. Can anyone explain why it is necessary to have those boxes checked when running the Calibration? I'm using a CCD camera (PL8300) and I think I remember that I didn't have those boxes checked when using a CMOS camera?
Title: Re: SubFrameSelector Warning (No Convergence)
Post by: pfile on 2018 October 18 22:41:42
optimize and calibrate for the dark?

if the master dark was not bias-subtracted, then if you want to scale it, you need to bias subtract it at ImageCalibration runtime. that is what "calibrate" means in the dark configuration. also, if you've loaded an uncalibrated (non-bias subtracted) master dark, then you should uncheck the master bias frame if you don't check 'calibrate'. otherwise you'll do a double bias subtraction.

"optimize" means to scale the dark to minimize the noise in the calibrated light. if your dark duration does not match the light duration, then it's probably a good idea to optimize the dark because otherwise you'll subtract too much dark signal from the lights.

rob
Title: Re: SubFrameSelector Warning (No Convergence)
Post by: GeneralT001 on 2018 October 19 14:38:51
Many thanks for the explanation. Most appreciated :)