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Pixinsight Dynamic Background

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8 replies to this topic

#1 ehanes7612

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Posted 20 March 2019 - 04:02 AM

I live for this feature on PI. I use it all the time. Today, I used it after I stretched the image and got back better results than using it before stretching ..a more even gradient in the background, which is hard for me since I live in the city and my images have a lot of light pollution. 


Edited by ehanes7612, 20 March 2019 - 04:03 AM.

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#2 terry59

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Posted 20 March 2019 - 06:34 AM

Yes, I find DBE useful for extracting color gradient from a stretched  image

 

waytogo.gif


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#3 elmiko

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Posted 20 March 2019 - 09:21 AM

Yesterday I was processing M 64 using Pixinsite. The data was captured with a triplet refractor, OSC camera using a field flattener and a light pollution filter. After an initial stretch in Pixinsite the background is always light blue. My usual work flow.. I applied DBE, then went on to remove some noise in the background with a luminense mask and MSLT. Background neutralization, Color Calibration. When I applied the CC the background turned blue again!?? This has never happened before.

After a few more redos, thinking that I did something wrong, same result?? I finally just reapplied the DBE and Voila! All was fixed! I have never used it on a Non Linear image though. Interesting.

Mike


Edited by elmiko, 20 March 2019 - 09:21 AM.


#4 bobzeq25

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Posted 20 March 2019 - 09:56 AM

I too use DBE (sometimes ABE) to reduce the effects of light pollution in my Red Zone.  Always as the first step in processing the stack (there's maybe a crop before).  The mathematics work better on linear data, I have no clue why some above have found it more effective on stretched data.

 

I pretty much don't use light pollution filters.  In my experience they remove too much data, make color processing difficult.



#5 H-Alfa

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Posted 20 March 2019 - 10:15 AM

Elmiko, in the documentation of the PPC there's and advice about the importance of having a good gradients correction.
https://pixinsight.c.../PCC/index.html
Maybe this is applicable to CC also and that's why it turned your background blue again?

By the way. Does anyone use DBE with fixed values? I discovered this feature some weeks ago and it's wonderful also, specially useful on images with a background full of nebulosity...

Enviado desde mi MI 5X mediante Tapatalk
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#6 elmiko

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Posted 20 March 2019 - 10:48 AM

You know I was thinking about something like that. Just couldn't figure out how to fix it. I did try photo metric Calibration. Got the same result.

Thanks Alberto


Edited by elmiko, 20 March 2019 - 10:50 AM.

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#7 Peregrinatum

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Posted 20 March 2019 - 01:20 PM

Do any of you use DBE with 'subtraction' and also with 'division' to reduce different parts of the background?


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#8 WadeH237

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Posted 20 March 2019 - 01:33 PM

When I applied the CC the background turned blue again!?? This has never happened before.

This probably has something to do with your screen transfer function, particularly whether the channels are linked, and whether "track view" is selected or not.

 

After you have done color calibration, go to the screen transfer function and hit the "reset" icon.  Then make sure that the channels are linked.  Enable "track view" and click on your color calibrated image to ensure that it is selected.  Finally, hit the "auto stretch" button.

 

What you see will be the result of your color calibration.


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#9 elmiko

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Posted 20 March 2019 - 04:31 PM

Thanks WadeH237, I think you may have hit the nail on the head. The other day I was playing around with the STF . I unlinked the the image to see what my newly pre processed stack looked like. I probably forgot to link the button after. I usually don't even use that tool. When I stretch an image I do it manually with the Histo tool. I get more control.

Thanks again  Mike




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