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Post your Pixinsight Processing Flow!

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#201 AnakChan

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Posted 22 October 2020 - 07:29 AM

Q: If I had Lum of different durations from different nights, I'd gather I'd be able to process each evening's set at least up to the Cosmetic Correction stage. But thereafter, w.r.t. Chris Foster's workflow, would I combine all the different night's worth of Lum subs into one big list to rank in the Subframe Selectioin stage? Or would I still have separate Subframe Selections for each night's worth of Lum? And further downstream to the Local Normalisation stage, would I have one big combined list for the Local Normalisation reference to run against, or would each night's worth ofd Lum have it's own Local Normalisation step?



#202 cfosterstars

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Posted 22 October 2020 - 01:28 PM

I am following your book.  Thanks.  I have a discrete set of Lights, Darks, DarkFlats and Flats.  Each now with matching parameters.  They are narrow band data from two weeks ago.  I have a good library through cosmetic corrections.  I need to maybe repeat this a few times to make it routine.  My main weakness around this is a coherent filing structure.

 

I need to figure out short cuts and batch processes to do simple things like bulk flipping images that came from meridian flips and rejecting bad subs in an easier manor. 

 

There is some details I need to learn about gain and offsets and where to very them between bright, dim, rgb, nb ect.

 

It would be nice to see a graphic cheat sheet work flow.  So far your book is very much of what I need to learn CMOS processing.  I'm just scratching the surface.   I've been using nebulosity and it is sooo easy to produce a pretty picture but I'm out growing it and need ways to get around some major obstacles. 

 

The help here as usual is very much appreciated.

There is no need to batch subs for meridian flips. PI staralignment will do that for you - just put them all in there. Use BLINK to cull bad subs right after calibration.



#203 cfosterstars

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Posted 22 October 2020 - 01:56 PM

Q: If I had Lum of different durations from different nights, I'd gather I'd be able to process each evening's set at least up to the Cosmetic Correction stage. But thereafter, w.r.t. Chris Foster's workflow, would I combine all the different night's worth of Lum subs into one big list to rank in the Subframe Selectioin stage? Or would I still have separate Subframe Selections for each night's worth of Lum? And further downstream to the Local Normalisation stage, would I have one big combined list for the Local Normalisation reference to run against, or would each night's worth ofd Lum have it's own Local Normalisation step?

As long as the temperature and gain are the same and only the integation time is different, you can just run them all at the same time. They will need to calibrated with different dark frames since they are different times, but once callibrated, you can run them together. SubframeSelector will weight them on S/N so that the better subs get more weight. I put all nights together into one batch. 

 

For LNorm, YOu just need to create a good master. I take the top 10-15 subs and create an integrated LNorm_reference image that is very clean. I use that reference and run all subs for all nights at the same time. I do NOT separate processing for different nights at all.


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#204 Linwood

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Posted 22 October 2020 - 01:59 PM

For LNorm, YOu just need to create a good master. I take the top 10-15 subs and create an integrated LNorm_reference image that is very clean. I use that reference and run all subs for all nights at the same time. I do NOT separate processing for different nights at all.

How do you choose those -- least eccentricity, best SNR, best FWHM?  Same weighting formula you use for Subframe Selector?   I have had lousy luck with local normalization generally, though I had been picking a single sub.



#205 cfosterstars

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Posted 22 October 2020 - 03:51 PM

How do you choose those -- least eccentricity, best SNR, best FWHM?  Same weighting formula you use for Subframe Selector?   I have had lousy luck with local normalization generally, though I had been picking a single sub.

This is a very personal choice. For the LNorm reference I use the same weighting formula from SubframeSelector. I integrate the top 10-15 subframes. The need to be clean frames. LNOrm takes some getting use to and I set the scale factor to 256 pixels, but basically have no issues with it. I cover this in the book in detail. 



#206 AnakChan

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Posted 23 October 2020 - 01:56 AM

As long as the temperature and gain are the same and only the integation time is different, you can just run them all at the same time. They will need to calibrated with different dark frames since they are different times, but once callibrated, you can run them together. SubframeSelector will weight them on S/N so that the better subs get more weight. I put all nights together into one batch. 

 

For LNorm, YOu just need to create a good master. I take the top 10-15 subs and create an integrated LNorm_reference image that is very clean. I use that reference and run all subs for all nights at the same time. I do NOT separate processing for different nights at all.

Thank you Chris. I've processed until the Cosmetic Correction part for each night's worth of light subs, since that requires the respective matching durations of each Master Dark. Similarly, due to different exposure durations collected each night, the hot/cold pixel thresholds would also vary.

 

 

The output of each batch of Cosmetic Corrected lights can all be lumped together and processed as one batch in Subframe Selector for weightings for Star Alignment. The original concern I had about LNorm was because each batch was collected in different locations, and more importantly under different Bortle sky levels (as such the varying exposure durations employed).

 

I would expect the LNorm Reference would be generated mostly from the subs from the location of Bortle 1 skies, and was concerned of what would happen if that got applied to the other light subs taken from the location of Bortle 5/6 skies.



#207 cfosterstars

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Posted 23 October 2020 - 06:31 AM

Thank you Chris. I've processed until the Cosmetic Correction part for each night's worth of light subs, since that requires the respective matching durations of each Master Dark. Similarly, due to different exposure durations collected each night, the hot/cold pixel thresholds would also vary.

 

 

The output of each batch of Cosmetic Corrected lights can all be lumped together and processed as one batch in Subframe Selector for weightings for Star Alignment. The original concern I had about LNorm was because each batch was collected in different locations, and more importantly under different Bortle sky levels (as such the varying exposure durations employed).

 

I would expect the LNorm Reference would be generated mostly from the subs from the location of Bortle 1 skies, and was concerned of what would happen if that got applied to the other light subs taken from the location of Bortle 5/6 skies.

I would think that the bortle1 reference would be better for all subs. It is even more ideal and that is what you want. you will have to just see what works.


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