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ELiminating poor subs with PI Blink and Subframe Selector


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Hi,
I'm new to PixInsight and have ben reading up about the above but have a few questions.

At least one tutorial suggests running calibration before using these tools. I use Astro Pixel Processor for pre-processing and have options to export subs after Calibration, the first step in the process, and also after Normalisation which is the last step before Registration.

Should I use the calibrated or normalised subs?

Second question, I don't know how calibration/normalisation works. If each sub is processed independently of the others I'm comfortable but I suspect each sub must be standardised (averaged) against the other subs at some point(s) in the process.

If this is the case then surely putting bad subs into pre-processing must adversely affect the good subs through this standardisation. In which case i'm thinking that Blinky and SS should be used prior to pre-processing?

I would be grateful for advice on when to use Blinky/SS and also what to look for.

I want to drop the worst frames, without being overwhelmed by science are there any simple rules/things to look for to acive this. FWHM and Noise seem to be key to me, can I just drop frames with outliers in these criteria?

Thanks
Jon 

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You can use blink on your raw files, it will put an autostretch over them so you can detect the main defects like eggshaped stars or big streaks. 

I usually run my calibration first, so script - batch preprocessing - load in all your flats, darks, bias and lights.

after that I run staralignment on them.

and after that I blink for defects.

 

your frames will still not be stretched, but you only need to throw away the obvious bad ones. Depends a bit on how picky you are about your data. Streaks from airplanes or sattelites will be erased by the clipping in the stacking process, so I leave those in.

you could blink the debayered frames if that works better for you, but then you need to eliminate the same frame in the raw subs, which you will use for stacking.

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