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2022-05-29: APP 2.0.0-beta2 has been released !

Release notes

Download links per platform:

windows 2.0.0-beta2

macOS x86_64 2.0.0-beta2

macOS arm64 M1 2.0.0-beta2

Linux DEB 2.0.0-beta2

Linux RPM 2.0.0-beta2

[Sticky] Ha + OIII Dual Narrowband Workflow

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(@shedastro)
White Dwarf Customer
Joined: 2 months ago
Posts: 16
Topic starter  
Posted by: @mabula-admin

To finish, I used the Star Reducer in APP with

correction radius 1.2

correct star halo 1.0

star size 65%

peak intensity 65%

noise threshold K=1 (means all stars above the noise floor are reduced)

Final Star Reducer

Wow, looks superb…..so it can be done…. Very appreciative of your time on this, I shall print out the instructions you have given here for reference….👍🏼

it’s just those sliders on the processing side of the window I can’t get me head around, they are not very intuitive to use, and the labels are not easy to understand, nor is the slider scales either, 0-10 would be much easier for each slider with full word descriptions on them…just my opinion of course…


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(@shedastro)
White Dwarf Customer
Joined: 2 months ago
Posts: 16
Topic starter  

There does seem to be a blue tinge to all the stars, is that normal…??


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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1723
 

@shedastro With a dual narrow band filter, also the stars will only have Ha and OIII data. Young hot stars are brighter in OIII than Ha so those will get a blue hue. In short, yes this is normal.


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(@shedastro)
White Dwarf Customer
Joined: 2 months ago
Posts: 16
Topic starter  
Posted by: @mabula-admin
Posted by: @shedastro

So from the original L-eXtrme data, how would I get the Ha and OIII individual stacks, when I first stack the data what do I choose, and I am talking way before I use the combine tool, do I stick with a certain formula, instead of just assigning the stack to RGB…??

In 0) Raw/FITS, you would get the H-alpha stack by setting the demosaic algorithm to Ha-O3 extract Ha 😉 . For O3, you use Ha-)3 extract O3.

Then those 2 stacks are the most optimal to use for Ha-O3 bicolor composite. You would load the Ha and O3 stacks into RGB Combine and again choose the HOO1 or HOO2 formula as a starting point 😉

 

So this would be better than using the “Ha- OIII colour” algorithm ..?

what would be the difference I guess the Ha - OIII colour would be quicker as it’s just one lot of stacking to do…?


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(@wvreeven)
Galaxy Admin
Joined: 4 years ago
Posts: 1723
 
Posted by: @shedastro

what would be the difference I guess the Ha - OIII colour would be quicker as it’s just one lot of stacking to do…?

That and you will only get one integrated RGB image instead of two integrated mono images. The two mono images will give you more flexibility in post-processing but, yes, one integration is faster. 


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(@shedastro)
White Dwarf Customer
Joined: 2 months ago
Posts: 16
Topic starter  
Posted by: @wvreeven
Posted by: @shedastro

what would be the difference I guess the Ha - OIII colour would be quicker as it’s just one lot of stacking to do…?

That and you will only get one integrated RGB image instead of two integrated mono images. The two mono images will give you more flexibility in post-processing but, yes, one integration is faster. 

Why would using the Ha - OIII colour algorithm give and integrated RGB image, surely it would be an Ha-OIII integration….??


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(@vincent-mod)
Quasar Admin
Joined: 5 years ago
Posts: 4850
 

Yes, but you still need RGB channels to display a RGB image on screen. So also with combining the two channels, you still mix some of the OIII in the green channel for example. The colour algorithm does this automatically with a certain preset. This is why doing it manually, like Wouter indicates, gives more flexibility on how to mix.


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(@mabula-admin)
Quasar Admin
Joined: 5 years ago
Posts: 3159
 

@shedastro BillyBoy, i have added to our todo list that we will add a channel unlink autostretch in a new redesigned preview filter 😉

Cheers,

Mabula


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(@shedastro)
White Dwarf Customer
Joined: 2 months ago
Posts: 16
Topic starter  

@mabula-admin 

ok, so you think this will be a useful feature then, what changed your mind…as I was under the impression you did not think it was needed….?

 


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(@mabula-admin)
Quasar Admin
Joined: 5 years ago
Posts: 3159
 

@shedastro, it definitely is not needed in the sense like you suggested in the start of this topic. But I will add it because it gives the user more options in preview stretching.


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(@anofeles)
White Dwarf Customer
Joined: 4 years ago
Posts: 18
 
Posted by: @mabula-admin

 

3) Kill background color noise, select ALL pixels from 0-background + 1*noise and check the selected pixels with the show color selection button :

Background noise Pixels

The weak H-alpha emmisions will not be harmed by this selection as can be seen in the mask :-). Those faint signals are visually above the noise level and that is represented by the background + 1*noise threshold. Simply set saturation to -100 which kills the color noise on the selected pixels.

I just learned how to remove background color noise. Thanks, but I have a little problem. Mabula explains that you have to move the saturation slider to -100. Is that only possible in beta 2.00? I can't install it because it doesn't run under MacOs Catalina (10.15.7) and in my version of APP (1.083.2), the saturation slider only goes from 0.00 to 0.50 and even if I move it to 0.00, I don't see any change in the background... Am I doing something wrong? Thanks in advance.


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(@mabula-admin)
Quasar Admin
Joined: 5 years ago
Posts: 3159
 
Posted by: @anofeles
Posted by: @mabula-admin

 

3) Kill background color noise, select ALL pixels from 0-background + 1*noise and check the selected pixels with the show color selection button :

Background noise Pixels

The weak H-alpha emmisions will not be harmed by this selection as can be seen in the mask :-). Those faint signals are visually above the noise level and that is represented by the background + 1*noise threshold. Simply set saturation to -100 which kills the color noise on the selected pixels.

I just learned how to remove background color noise. Thanks, but I have a little problem. Mabula explains that you have to move the saturation slider to -100. Is that only possible in beta 2.00? I can't install it because it doesn't run under MacOs Catalina (10.15.7) and in my version of APP (1.083.2), the saturation slider only goes from 0.00 to 0.50 and even if I move it to 0.00, I don't see any change in the background... Am I doing something wrong? Thanks in advance.

Hi @anofeles,

It is the saturation slider in the HSL selective Color from the Tools menu. Not the saturation slider of the preview filter on the right side ;-).

Please read all the posts leading to that result and it will become clear 😉 It does work in the previous 1.083 version as well.

Mabula


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