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Can PixInsight upsample flats?

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#1 Mark Bailey

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Posted 19 September 2021 - 12:17 PM

The utility of my observatory is much increased by using CCDAutoPilot. I have mostly used the program, along with TheSkyX, with a now vintage SBIG ST-10XME which works fine. I would also like to use my modified Canon Rebel, or maybe buy a color CMOS astro-camera, but one obstacle is that CCDAutoPilot cannot manage the exposure to create unbinned flats. It can seem to manage 2X2 binned flats.

 

I have been using CCDStack and have not tried out PixInsight. I am a lonely holdout, I know. Does anyone happen to know if PixInsight can use/upsample binned flats with unbinned lights? CCDStack can. DeepSkyStacker cannot.

 

Thanks much,

 

Mark


Edited by Mark Bailey, 19 September 2021 - 12:39 PM.


#2 andysea

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Posted 19 September 2021 - 01:25 PM

As far as I know flats, besides correcting for vignetting and dust, also correct for PRNU. This would suggest that there needs to be a 1x1 pixel match between lights and flats.

Edited by andysea, 19 September 2021 - 02:51 PM.

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#3 Mark Bailey

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Posted 19 September 2021 - 02:30 PM

As far as I know flats, besides correcting for vignetting and dust, also correct for PRNU, hot pixels etc... This would suggest that there needs to be a 1x1 pixel match between lights and flats.

Thanks, Andy. If PI can do the up-sampling, it would only be converting to a representative pseudo flat that should still help with vignetting.
 



#4 andysea

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Posted 19 September 2021 - 02:50 PM

I believe you can up sample with PI but I am not sure. I will check later and report back.
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#5 andysea

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Posted 19 September 2021 - 05:31 PM

Ok I Just checked, with pixinsight you can use the resample process to upsample or downsample an image as you like. 


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#6 Mark Bailey

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Posted 19 September 2021 - 06:54 PM

Thank you very much, Andy!



#7 ChrisWhite

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Posted 19 September 2021 - 06:58 PM

A better tool for upsampling and downsampling is IntegerResample.


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#8 andysea

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Posted 19 September 2021 - 07:20 PM

Thanks Chris! I never resample and I wasn't aware of that process.


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#9 Mark Bailey

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Posted 19 September 2021 - 07:56 PM

Thanks, Chris. Now to write that down somewhere where I will remember and can find it . . .



#10 sabant

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Posted 20 September 2021 - 06:39 AM

You can certainly upscale with Pixinsight, but -as others have said- you cannot use the flats of a ST-10 for a DSLR (different field of view). They will vignette differently. Nope, I am sorry, but that will not work.



#11 Mark Bailey

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Posted 20 September 2021 - 09:47 AM

- you cannot use the flats of a ST-10 for a DSLR (different field of view). They will vignette differently. Nope, I am sorry, but that will not work.

I did not say I was trying to use flats from the SBIG for the DSLR. As I did say, CCDAutoPilot can only make binned flats for the DSLR and I am wondering if PI could upsample them to work at some level with unbinned lights (from the DSLR!).




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