M20 Trifid Nebula Reprocessed

[Startrek (Martin)]

Here’s a reprocess of my M20 Trifid Nebula LRGB and LRGB with Ha Accent in Startools with the following changes -
Optimised the dynamic range by creating a larger region of interest (ROI) around the main structure during the AutoDev stretch.
Also omitted the “Isolate” algorithm in the Super Structure module which exposed more detail , mainly in the background outside the main object.

The reprocess has definitely lifted the image a bit compared to the original

Startools “will not clip your data” even though the background on my images sometimes appears somewhat darkish.

See attached link to Startools and it’s AutoDev ( stretch ) for an understanding of how it works ( including reference to black point and clipping ) ……,

https://www.startools.org/modules/autodev

Attached revisions in LRGB and LRGB with Ha Accent ( original frame , Crop version and Super Crop version )

Astrobin links below for full resolution…….,

https://www.astrobin.com/rde4nn/

https://www.astrobin.com/j05tfu/

Thanks for looking

Comments Welcome

Martin

[alpal]

Hi Martin,
well done - that's not clipped anymore and shows a lot more detail in the darker areas.
As for Startools - I've never used it so I don't know enough about it to comment.

I attach a picture of NASA FITS Liberator after I clicked on
Stretch function and you can see all the options to try.
I used to try many different options and just look at what it did.
If I wanted to bring out detail in dark areas I'd choose
the function x^(1/5).
Other times on bright nebulas , ArcSinH (x) stretch was good.

cheers
Allan

[Startrek (Martin)]

Originally Posted by alpal

Hi Martin,
well done - that's not clipped anymore and shows a lot more detail in the darker areas.
As for Startools - I've never used it so I don't know enough about it to comment.

I attach a picture of NASA FITS Liberator after I clicked on
Stretch function and you can see all the options to try.
I used to try many different options and just look at what it did.
If I wanted to bring out detail in dark areas I'd choose
the function x^(1/5).
Other times on bright nebulas , ArcSinH (x) stretch was good.

cheers
Allan

Thanks Allan,
I don’t expect you to comment on Startools AutoDev , just have a read ( if your interested) for your own information to understand how this particular stretch module works , it’s totally different from traditional non linear Histogram transformations.

Cheers
Martin