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Midnight_lightning

IC1805 - First HST Attempt

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Posted (edited)

This isn't going to win any prizes but I have been trying to work out how to process HST images for months and this is the first time I have come close to producing the image that I have in my mind. I'm using data from my initial NB attempts last year and I think there are calibration issues which are probably not helping but my processing needs work and I would be grateful for any tips.

This was my approach:

  • Register and Stack HA, OIII, SII in DSS
  • Process each colour in Star Tools (Crop, Autodev, Wipe, Dev, HDR, Decon, Sharpen, Life, Save)
  • Combine the three colours in Photoshop Elements Layers
    • Use Hue/Saturation layer set to colorise - Assign SII-Red; OIII-Blue; HA-Green
    • Use Colour Curve and Brightness/Contrast layers to adjust each colour
  • Use Star tools to remove fringing from stars and reduce stars, do noise reduction

I don't like using Elements for this as it's only 8 bit but I haven't worked out how to do it in Star Tools yet (or whether it can be done in Star Tools) and don't have anything else suitable.

I'm struggling to know how much processing to do before combining the three colours and what to do after, for example should I do Decon/Sharpen before or after combining the colours?

I would welcome any suggestions.

Thanks for looking

Jon

IC1805 HST 2.tif

IC1805-HST-2-1024.jpg

Edited by Midnight_lightning
  • Like 13

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Well Jon, what can I say. If this was my first NB final image I would be over the moon. It's a great attempt with fusions of colour. I have a great respect for Startools, for the price it's a steal and you have used it to great effect. When I was using Startools I could never get mt head around the Colours Module, I could never get it right on some of the images I was processing. But you certainly have. Great image.

Steve

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Sorry can’t offer advice, but I think it’s very nice!

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Yep, same here.   No suggestions, it looks great as it is.   Detailed structure in the cloud is particularly awesome.

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Great first narrowband image 👍🏻👍🏻 I combine my channels before doing any processing at all, then process them to the colours I like then use a processed Ha image as the luminance to bring out the detail. 😊 

Hope that helps 👍🏻

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Thanks for the kind comments, I think I have a way to go yet but the positive feedback has given me a boost to keep trying.

Steve, I didn't use the Colour Module much in this one though I know what you mean. If you haven't already tried it perhaps try the following.... Create a Star Mask including all stars of any significance, Go into Colour, Select Sample, Go back into Mask and Clear then Invert and Save. This uses the stars as basis for "White" and ST usually produces excellent colours based on this. It's best for RGB but worth a try for NB as well. I love Star Tools, easy to use initially but so much hidden depth that after two years I am still learning.

Sara, thanks for the tips, I will try those over the next couple of days. It would certainly save some time to only process after combining. I'll need to work out how to generate a luminance image from Ha but that makes a lot of sense, I think that will make quite a difference.

Jon

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Posted (edited)

I had another go at this following Sara's suggestions, I haven't tried the luminance layer yet but it's already looking better - I'm quite excited about it so thought I'd share.

I'm thinking I might try removing the stars prior to processing and adding them back in later, Melotte 15 is over-exposed and needs correcting, and I've overdone the noise reduction.

(Edit. I just noticed I haven't cropped some of the edges enough to remove alignment artefacts)

Ha light process NR.tif

Ha-light-process-pre-NR-1024.jpg

Edited by Midnight_lightning
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That's looking much better already :) 

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And another attempt.....

I'm finding HST processing a real challenge but the tools in Affinity are much better than Elements and I think I am learning (slowly).

Does anyone know how to do star reduction in Affinity?

Thanks

Jon

IC1805 HST Large.jpg

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Nice! Can't help with star reduction in affinity, I'm afraid.

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25 minutes ago, Midnight_lightning said:

And another attempt.....

I'm finding HST processing a real challenge but the tools in Affinity are much better than Elements and I think I am learning (slowly).

Does anyone know how to do star reduction in Affinity?

Thanks

Jon

IC1805 HST Large.jpg

This is very nice Jon. Lovely soft brown dust framing the golden heart and blue centre.  

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Very impressive Jon, clearly StarTools does have hidden depths well beyond the default settings approach, I definitely have a lot to learn on the colours module.

I didn’t think I would get into narrowband but I have been pleasantly surprised by how much detail can be pulled out in Ha on the right target, particularly under less than ideal conditions.

Of course for full narrowband I am now regretting buying a camera with only an integral 5 position filter wheel, any prospective mono camera purchasers out there, get a 7 position!

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Posted (edited)

I agree entirely about the filter wheel, I only bought 5 position and would say it’s the only part  of my rig that I got wrong. Should have got 7 position. That said I am going to experiment with bicolour NB which means I can keep RGBHaOiii in my FW. Check out what Steve Cannistra has achieved with bicolour using a synthetic SII layer ?

I only used the Star Tools Wipe, Develop and Heal modules for this one, all the colour work was done in Affinity. That said, I rate ST very highly and when I do RGB that’s usually all I use. It’s a doddle to use on defaults but does indeed have a lot of depth when you get into it. Try this In the colour module - generate star mask, go into Colour and keep mask. Click sample then Mask. Clear and invert mask and Keep. For most RGB this gives an excellent starting point. Cap green to yellow also works wonders.

Thanks for the comments - NB rocks, good luck.

Edited by Midnight_lightning

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