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Same data, different processing: the Wizard Nebula

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#1 fmeschia

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Posted 20 April 2019 - 06:46 PM

Last September, in my first outing with a new-to-me Nikon D5300, I collected 96 minutes of the Wizard Nebula via my AT130EDT from a dark site.

 

Back then I processed the image using my then-normal workflow and I was never satisfied with the results. The Wizard Nebula is faint, especially for a non-modified DSLR, and it sits in the middle of the Milky Way, so it is overwhelmed by the stars all around it. I made several attempts by using Morphological Transformation in PixInsight to reduce the “importance" of the stars, but I would get unpleasing star artifacts and, in general, a washed-out appearance, like here:

 

44587805991_7b7e96ff49_c.jpg

 

In these past few months, however, I have learned a few new tricks in PixInsight, among which the use of the Arcsinh stretch, and Adam Block’s technique for star de-emphasis (see https://youtu.be/SPFsoO0ZWeg?t=3679). Today I re-processed the same data set using those new methods, and I was blown away by the improvement:

 

32711820867_fe5b5a2852_c_d.jpg

 

Astrobin:

get.jpg?insecure

 

What do you think? Comments are very very welcome.

 

Francesco


Edited by fmeschia, 21 April 2019 - 01:05 AM.

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#2 moxican

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Posted 20 April 2019 - 07:13 PM

I like the second image better. First it looks more natural in terms of color and smoother for appearance. Second, the stars are controlled much better in the second image. Good work



#3 Astroman007

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Posted 20 April 2019 - 08:07 PM

Stunning both! Though just for color, I agree with Gus above me; I prefer the second version.



#4 zakry3323

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Posted 20 April 2019 - 08:48 PM

The difference is that the first take is only 96 minutes integration time. The reprocessed one is ONLY 96 MINUTES integration time??!! 



#5 fmeschia

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Posted 20 April 2019 - 09:05 PM

The difference is that the first take is only 96 minutes integration time. The reprocessed one is ONLY 96 MINUTES integration time??!!

Yes the starting data file is exactly the same in both, so is the underlying data. Only the two workflows differ, and only in the non-linear (stretched) portion.


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#6 zakry3323

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Posted 20 April 2019 - 09:34 PM

Yes the starting data file is exactly the same in both, so is the underlying data. Only the two workflows differ, and only in the non-linear (stretched) portion.

It's a night and day difference, so to speak! Thanks for sharing the link! 


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#7 ngc1535

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Posted 20 April 2019 - 10:53 PM

Well...I for one, could not be more pleased!! As far as I know you are the first "documented" astroimager to use my technique. 

I am very happy someone else could reproduced my steps and use them beneficially. It is one thing to create an innovation- it is quite another thing to have someone use it can say it helped!

Quite a happy day for me. 

 

I intend to create a post for the PI forum. With your permission, It would be great to highlight your excellent work.

 

Sincerely,

Adam Block

 

http://AdamBlockStudios.com


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#8 fmeschia

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Posted 20 April 2019 - 11:22 PM

Well...I for one, could not be more pleased!! As far as I know you are the first "documented" astroimager to use my technique. 

I am very happy someone else could reproduced my steps and use them beneficially. It is one thing to create an innovation- it is quite another thing to have someone use it can say it helped!

Quite a happy day for me. 

 

I intend to create a post for the PI forum. With your permission, It would be great to highlight your excellent work.

 

Sincerely,

Adam Block

 

http://AdamBlockStudios.com

Adam, I’d be honored. Thanks for inventing and sharing your technique. Inventing is already an accomplishment, sharing is progress.

Francesco


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#9 fmeschia

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Posted 21 April 2019 - 12:16 AM

And for reference, this is the same dataset, stretched with Arcsinh but BEFORE processing with Adam’s de-emphasis. I think the stars distract from the nebula quite a bit.

 

Wizard-10a.jpg

Edited by fmeschia, 21 April 2019 - 12:31 AM.

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