OIII Improvment - NGC7635 Bubble Nebula - Forums

Topic starter

Nov 6, 2023

Hello,

I have a question regarding the Bubble Nebula. How can I improve the OIII component around the bubble? The signal is actually there.

I find it super challenging, even though I initially pre-stretched both components separately, and OIII was more visible. After combining the narrowband images using Pixelmath, I get a lot H-Alpha signal, and the OIII is hardly noticeable.

What methods do you use here? I primarily use Siril, Affinity Photo, and Gimp.

I'm using the following Pixelmath formula to combine Ha/OIII:

R = Ha
G = ((OIIIHa) ^ ~(OIIIHa)) * Ha + ~((OIIIHa) ^ ~(OIIIHa)) * OIII
B = OIII

Here is the result of my project. Perhaps someone has a tip:

Bubble Nebula

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Brian Puhl

IOTD Staff

Nov 6, 2023

Why not use HOO instead of that formula for green that you're using? That would definitely kill some of the Oiii signal.

David Moore

Nov 6, 2023

Maybe this Pixinsight tutorial will help? I found the 1st one useful and I have recently tried the Bubble nebula but not submited it yet.
https://pixinsight.com/forum/index.php?threads/narrowband-video-tutorials-first-three-parts.21780/

David Néel

Nov 6, 2023

OP seems not to have pixinsight. Otherwise I'll suggest to use narrowband normalization. Lukomatico made a good how to on it.

Rajat Kumar

Nov 6, 2023

Dominik, I think you just need to add more OIII signal. A lot more integration time. Once you have enough OIII data in your image, perhaps, it would become easy to colour balance and bring out the contrast you are looking for.

Also, I am just one image old when it comes to dual narrowband data processing. Just my two cents.

Clear skies!

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Brian Puhl

IOTD Staff

Nov 6, 2023

For what it's worth, his image looks fine. The colors are about as to be expected, but the addition of Ha signal in the green channel doesn't really make alot of sense to me. I think what OP wants is more 'blue' where his Oiii signal is, but that's really just not happening on this target. Colors blend, every place that has Oiii signal in bubble, also has Ha signal. Blue + Red = pink. Fix the green channel to be only Oiii and you'll still have pretty much the same image.

If you want more contrast in the colors, simply play with curves. There's no need for fancy scripts. Bubble just isn't a dramatically colorful target in HOO.

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Dominik

Topic starter

Nov 7, 2023

Brian Puhl:
For what it's worth, his image looks fine. The colors are about as to be expected, but the addition of Ha signal in the green channel doesn't really make alot of sense to me. I think what OP wants is more 'blue' where his Oiii signal is, but that's really just not happening on this target. Colors blend, every place that has Oiii signal in bubble, also has Ha signal. Blue + Red = pink. Fix the green channel to be only Oiii and you'll still have pretty much the same image.

If you want more contrast in the colors, simply play with curves. There's no need for fancy scripts. Bubble just isn't a dramatically colorful target in HOO.

I will give it a try.

Another option would be to simply combine Ha and OIII and extract RGB from that. Using individual color channels could potentially give me more control and allow me to work with curves as suggested.

Thank you Brian.

CS
Dominik

Brian Puhl

IOTD Staff

Nov 7, 2023

Dominik:
Brian Puhl:
For what it's worth, his image looks fine. The colors are about as to be expected, but the addition of Ha signal in the green channel doesn't really make alot of sense to me. I think what OP wants is more 'blue' where his Oiii signal is, but that's really just not happening on this target. Colors blend, every place that has Oiii signal in bubble, also has Ha signal. Blue + Red = pink. Fix the green channel to be only Oiii and you'll still have pretty much the same image.

If you want more contrast in the colors, simply play with curves. There's no need for fancy scripts. Bubble just isn't a dramatically colorful target in HOO.

I will give it a try.

Another option would be to simply combine Ha and OIII and extract RGB from that. Using individual color channels could potentially give me more control and allow me to work with curves as suggested.

Thank you Brian.

CS
Dominik

I'm confused, you want to combine Ha and Oiii then extract them again? You're not making any sense here.

Dominik

Topic starter

Nov 7, 2023

Brian Puhl:
Dominik:
Brian Puhl:
For what it's worth, his image looks fine.    The colors are about as to be expected, but the addition of Ha signal in the green channel doesn't really make alot of sense to me.       I think what OP wants is more 'blue' where his Oiii signal is, but that's really just not happening on this target.    Colors blend, every place that has Oiii signal in bubble, also has Ha signal.    Blue + Red = pink.   Fix the green channel to be only Oiii and you'll still have pretty much the same image.

If you want more contrast in the colors, simply play with curves.     There's no need for fancy scripts.    Bubble just isn't a dramatically colorful target in HOO.

I will give it a try.

Another option would be to simply combine Ha and OIII and extract RGB from that. Using individual color channels could potentially give me more control and allow me to work with curves as suggested.

Thank you Brian.

CS
Dominik

I'm confused, you want to combine Ha and Oiii then extract them again?   You're not making any sense here.

I've reconsidered and you're correct. It wouldn't be practical. It would be an better option to combine the narrowband data directly in Gimp or Photoshop and make adjustments. This should offer greater flexibility and be more user-friendly compared to using Pixelmath.

But, as you mentioned, the question remains whether it makes sense for this target without a monochrome camera and sufficient integration time for the blue channel. At the Bubble the Ha is indeed very dominant.

CS
Dominik

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Brian Puhl

IOTD Staff

Nov 7, 2023

Dominik:
Brian Puhl:
Dominik:
Brian Puhl:
For what it's worth, his image looks fine.    The colors are about as to be expected, but the addition of Ha signal in the green channel doesn't really make alot of sense to me.       I think what OP wants is more 'blue' where his Oiii signal is, but that's really just not happening on this target.    Colors blend, every place that has Oiii signal in bubble, also has Ha signal.    Blue + Red = pink.   Fix the green channel to be only Oiii and you'll still have pretty much the same image.

If you want more contrast in the colors, simply play with curves.     There's no need for fancy scripts.    Bubble just isn't a dramatically colorful target in HOO.

I will give it a try.

Another option would be to simply combine Ha and OIII and extract RGB from that. Using individual color channels could potentially give me more control and allow me to work with curves as suggested.

Thank you Brian.

CS
Dominik

I'm confused, you want to combine Ha and Oiii then extract them again?   You're not making any sense here.

I've reconsidered and you're correct. It wouldn't be practical. It would be an better option to combine the narrowband data directly in Gimp or Photoshop and make adjustments. This should offer greater flexibility and be more user-friendly compared to using Pixelmath.

But, as you mentioned, the question remains whether it makes sense for this target without a monochrome camera and sufficient integration time for the blue channel. At the Bubble the Ha is indeed very dominant.

CS
Dominik

Between you and me, I think you might have an unrealistic expectation of what your options are with the HOO palette. Just because oxygen gets mapped to blue/green doesn't mean it's going to magically make that area blue/green. You would need an absence of Ha signal for that to occur. The images that you may see where the bubble is blue are SHO palette. Since you don't have sulfur, you won't be able to make that work.

The natural color of Bubble is red, which coincides to the strong Ha signal. Astrophotography is art, so ultimately it's up to the artist, but I wouldn't try and make it something it's not.

I just completed a composition of Bubble myself. Have a look. https://www.astrobin.com/8q0aok/

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Dominik

Topic starter

Nov 7, 2023 · Edited: Nov 7, 2023

Brian Puhl:
Dominik:
Brian Puhl:
Dominik:
Brian Puhl:
For what it's worth, his image looks fine.    The colors are about as to be expected, but the addition of Ha signal in the green channel doesn't really make alot of sense to me.       I think what OP wants is more 'blue' where his Oiii signal is, but that's really just not happening on this target.    Colors blend, every place that has Oiii signal in bubble, also has Ha signal.    Blue + Red = pink.   Fix the green channel to be only Oiii and you'll still have pretty much the same image.

If you want more contrast in the colors, simply play with curves.     There's no need for fancy scripts.    Bubble just isn't a dramatically colorful target in HOO.

I will give it a try.

Another option would be to simply combine Ha and OIII and extract RGB from that. Using individual color channels could potentially give me more control and allow me to work with curves as suggested.

Thank you Brian.

CS
Dominik

I'm confused, you want to combine Ha and Oiii then extract them again?   You're not making any sense here.

I've reconsidered and you're correct. It wouldn't be practical. It would be an better option to combine the narrowband data directly in Gimp or Photoshop and make adjustments. This should offer greater flexibility and be more user-friendly compared to using Pixelmath.

But, as you mentioned, the question remains whether it makes sense for this target without a monochrome camera and sufficient integration time for the blue channel. At the Bubble the Ha is indeed very dominant.

CS
Dominik

Between you and me, I think you might have an unrealistic expectation of what your options are with the HOO palette. Just because oxygen gets mapped to blue/green doesn't mean it's going to magically make that area blue/green. You would need an absence of Ha signal for that to occur. The images that you may see where the bubble is blue are SHO palette. Since you don't have sulfur, you won't be able to make that work.

The natural color of Bubble is red, which coincides to the strong Ha signal. Astrophotography is art, so ultimately it's up to the artist, but I wouldn't try and make it something it's not.

I just completed a composition of Bubble myself. Have a look.  https://www.astrobin.com/8q0aok/

Okay,

thank you for the clarification. I think I've got it now.

A region with a pure oxygen component will appear blue, while one with hydrogen alpha will be red. Once hydrogen and oxygen are mixed, the color accents are determined by the colors produced by the excited gases and the hydrogen/oxygen ratio in the area.

I thought there might be a way to artificially adjust the ratio of the colors and there would be more options here.

By the way, I really like your picture, the details, the natural colors and the star colors. Very beautiful and impressive.

CS
Dominik

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Christian Großmann

Nov 7, 2023 · Edited: Nov 7, 2023

Hi,

this is an interesting conversation for me. This year, I collected a lot of data of the bubble nebula myself. After I stacked the HSO data, I tried to combine them in different palettes. It was really sad. I simply couldn't find a somewhat pleasing starting point. I tried to combine the data in the Forrax and the usual HSO palette, but in both versions, I was never satisfied with the results. My processing skills are not on a high level though, but with other subjects I got much better results for my taste.

Anyway, I looked at some images here on AstroBin and it seems that the Bubble Nebula is color wise a quite "difficult to handle" target. It seems, I'm not alone with my problems. It's just sad, that I got 50 hours of HSO data, but I'm not able to process the final image the way I like it. Although it's only HOO, I also got 30 hours of data of the Crescent Nebula at the same time I did the bubble, but this image turned out really great. Maybe that's just how life goes.

In the end, I could've guessed it from what I saw in advance. But I thought, maybe I can do better.

This message does not solve any of your problems. Nor does it solve mine. I just had to learn, that some targets won't work as expected.

I just wanted to share my frustration with somebody. Please, just ignore me…

CS

Christian

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Adrian

Nov 7, 2023 · Edited: Nov 7, 2023

[deleted]

Chris H

Nov 7, 2023

I’m not sure if this is helpful, but I ran into the same issue about a month ago. I did something like this in Pixinsight:
Create master Ha, Oiii, R,G and B images
Run DBE, Blur X terminator, etc on each
Create a channel combined RGB image, run color calibration, then extract stars to use later
Create channel combination HOO (Ha and Oiii) image, then extract stars
create a luminance layer from Ha to use later
On the narrowband HOO image run denoise, etc.Now the image is mainly red, but the bubble area is brighter. Create a mask that covers just the bubble and surrounding area you want to add some blue. Now invert the mask and mess around with curves transformation, reducing the red and adding blue to just that area. Once you get some blue, remove the mask and add in the Ha luminance layer. Finally, add back the RGB stars.

I am no expert, but was happy for this result.
Chris
https://www.astrobin.com/ofcufi/

Helpful

Marcelo Muñoz

Nov 8, 2023

A while ago I developed a generalization of the dynamic palettes created Cloudy Night. This development could help you with what you are looking for. The equations were included in a script developed by Raúl Hussein from the Astrocitas YouTube channel. Here I leave the respective links of the development and the script.
https://www.youtube.com/watch?v=YKbgAAj0P34&t=1741s
https://www.youtube.com/watch?v=VmM8R5phLNw&t=926s