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Toning bright cores like M42 trapezium.

Posted: Sat Feb 25, 2017 12:17 pm
by davejerr
Hello,
I imaged 2 sets of exposures on M42.
1) to bring out detail on larger area.
2) short exposures to get the 4 stars in the trapezium.
The 4 stars where clear in the exposures.
how do i get startools to help obtain the trapezium detail. :idea:
What are the steps to follow to get this result.
I have to admit i find the Layers and color modules a bit difficult to use. :confusion-shrug:

Regards
Dave Jerrams

Re: Toning bright cores like M42 trapezium.

Posted: Mon Feb 27, 2017 1:52 am
by admin
Hi Dave,

Is this thread of any use?

The Layer module is indeed not for the faint hearted - it is a more user firendly (i.e. it has a GUI) version of traditional Pixel Math.

What sort of trouble are you running into in the Color module?

Thanks,

Re: Toning bright cores like M42 trapezium.

Posted: Mon Feb 27, 2017 12:30 pm
by davejerr
Hi
Ivor, its an honor to have you dealing with my issue.
the link will help me deal with multi length exposures.
It seems i have to use a different methodology in DSS,i.e the Entropy Stack method
So to conclude load FITS fro DSS into Startools as per normal,and process normally and use the Layers module.

Color Module.
The sample steps.
I have it as Enter Color module- mask-auto-keep.
back to color module-sample and then back to mask & invert,then back color module.
The steps are not clear to me,as results always seem overblown.
I feel bad having you deal with my little problem when you should be busy working on the bigger startools picture.
Cheers
Dave : :)

Re: Toning bright cores like M42 trapezium.

Posted: Tue Feb 28, 2017 11:35 pm
by admin
No problem Dave.
davejerr wrote:Hi
It seems i have to use a different methodology in DSS,i.e the Entropy Stack method
So to conclude load FITS fro DSS into Startools as per normal,and process normally and use the Layers module.
Actually, you should just be stacking with Median Kappa-Sigma Clipping, Kappa-Sigma Clipping, Median or Average methods.
You'd be creating 2 stacks; one stack with all the short exposure light frames and one stack with all the long exposure light frames.

Be sure to use the first completed stack as a reference frame for when you are stacking the second stack. This way all the stars will align across both stacks and you will end up with two stacks that are equal in size/resolution + have stars in the exact same place.

Now you can perform the Layer module trick from the mentioned thread.
Color Module.
The sample steps.
I have it as Enter Color module- mask-auto-keep.
back to color module-sample and then back to mask & invert,then back color module.
The steps are not clear to me,as results always seem overblown.
There are a number of different ways to color calibrate your image (see here)

If you are creating a mask then it sounds like you are trying to use the star field sampling method (I am also assuming you are performing this color calibration towards the end of your processing, just before tuning off Trracking?).
The steps are indeed correct (the "Fat Stars" preset will likely yield the best star field to sample color from).

"Overblown" can mean a lot of things, but if you mean the colors are too saturated you can use the "Saturation amount", "Bright Saturation" and "Dark Saturation" parameters to control this.

If by "Overblown" you mean the color balance is incorrect (sampling stars that suffer from chromatic aberration can cause this), then see if you have more success with the other methods of color calibration.
I feel bad having you deal with my little problem when you should be busy working on the bigger startools picture.
No worries - proper support and helping each other is part of that bigger picture! :)

Clear skies!

Re: Toning bright cores like M42 trapezium.

Posted: Mon Mar 06, 2017 7:44 am
by davejerr
Hello Ivo,
The links and info have helped.
Experimented with prcocedures and came up a nice M42 composite.Trapezium has some detail and a nice blueish hue to it.
I have attached a jpeg if the composite
Will also post the steps that i used hoping that it will be useful to other users.
Image is 2 DSS stacks of 20x iso400 20 secs subs,20 x iso800 300 secs subs with calibration frames
Cheers
Dave

Re: Toning bright cores like M42 trapezium.

Posted: Mon Mar 06, 2017 7:48 am
by davejerr
Hello,
sorry it seems i did not attach the jpeg correctly
Here goes
Regards
Dave ;)

Re: Toning bright cores like M42 trapezium.

Posted: Mon Mar 06, 2017 10:20 pm
by admin
That's a very, very good result! :thumbsup:

Have you tried applying some deconvolution to the core?

Re: Toning bright cores like M42 trapezium.

Posted: Tue Mar 07, 2017 7:54 am
by davejerr
Hello,
Will certainly go through some Decon.
now that i can use the layers module, i am going to reprocess these stacks deeply over the coming weekend.

Thanks again for your help and input

Its nice to see product devolpers directly involved even in moan groan forum pages.
You guys are great.

Regards
Dave :D