IC1396 Elephant's Trunk Nebula - SHO

[Richard_]

IC1396 Elephant's Trunk nebula shot in monochrome narrowband.

Integration time is roughly 10hr total for SHO:

• S    3h 45m
• H   3h
• O   3h 15m

Shot from backyard in Bortle 5 zone and processed with full suite of Russell Crowman AI tools and Narrowband Normalisation process in Pixinsight. I really enjoyed using the Narrowband Normalisation process. Previously, I would have to wrestle with colour masking and hue to get the pallette I wanted, but this process allows independant boosting of the SII and OIII signals. I'd like to have more data but due to the abysmal weather, these three imaging sessions across September and October 2023 are the only sessions I've had since May 2023, so this will have to do for now!

See below link for acquisition details and equipment used Comments and feedback welcomed!

https://www.astrobin.com/ltlkj5/

[glafnazur]

That looks really nice 👍

[windjammer]

That is seriously fabulous!  My only comment would be about the stars - shapes and edges nicely judged, but they have a colour cast that follows the nebula ?  No idea how to fix it, NB star colours a law unto themselves!

Simon

[Richard_]

Yeah that's narrowband stars for you! I did remove them via StarXterminator after stretching so when I was adjusting the colour of the nebulosity, it shouldn't have affected the star colour. I did use the Correct Magenta Stars script to remove typical purple cast on SHO NB stars but maybe there's a few tricks to improve the star colour?

I did want to replace them with RGB stars but I don't know when I'll be able to image next. I can live with these stars for now

Edited October 24, 2023 by Richard_

[assouptro]

1 hour ago, Richard_ said:

Yeah that's narrowband stars for you! I did remove them via StarXterminator after stretching so when I was adjusting the colour of the nebulosity, it shouldn't have affected the star colour. I did use the Correct Magenta Stars script to remove typical purple cast on SHO NB stars but maybe there's a few tricks to improve the star colour?

I did want to replace them with RGB stars but I don't know when I'll be able to image next. I can live with these stars for now

Hi Richard 

great image! 
it’s a shame the weather has been so poor recently, I hope we get some clearer weather soon (probably the next full moon!) 

I just thought I’d mention a method I saw for improving star colour in narrowband images, it was a YouTube instruction by James Lamb regarding creating a Hubble pallet from an OSC camera, I’m not sure why I was watching it as I don’t even own a OSC camera! Probably due to the weather and lack of clear skies?! 
Anyway, you may already be using this method, or be aware of it, but if not, it’s spectrophotometricColorCalibration

I’ll pop a link here, it’s what he does about 9 minutes in that I found informative 

Anyway, as I said 

fab image!! 
 

cheers 

Bryan 

[Richard_]

37 minutes ago, assouptro said:

Hi Richard 

great image! 
it’s a shame the weather has been so poor recently, I hope we get some clearer weather soon (probably the next full moon!) 

I just thought I’d mention a method I saw for improving star colour in narrowband images, it was a YouTube instruction by James Lamb regarding creating a Hubble pallet from an OSC camera, I’m not sure why I was watching it as I don’t even own a OSC camera! Probably due to the weather and lack of clear skies?! 
Anyway, you may already be using this method, or be aware of it, but if not, it’s spectrophotometricColorCalibration

I’ll pop a link here, it’s what he does about 9 minutes in that I found informative 

Anyway, as I said 

fab image!! 
 

cheers 

Bryan 

Thanks for the suggestion Bryan! I've used SPCC for my LRGB/RGB images but I haven't used it for SHO as I use the "Narrowband Normalization" process for managing colours of the SHO nebulosity.

Perhaps it may be useful to make a clone of my image and perform SPCC just to correct star colours, then take the stars out of that image and insert into my processed, starless image? Do you have any experience in this approach? 

[assouptro]

1 hour ago, Richard_ said:

Thanks for the suggestion Bryan! I've used SPCC for my LRGB/RGB images but I haven't used it for SHO as I use the "Narrowband Normalization" process for managing colours of the SHO nebulosity.

Perhaps it may be useful to make a clone of my image and perform SPCC just to correct star colours, then take the stars out of that image and insert into my processed, starless image? Do you have any experience in this approach? 

I’ve only had one go at it so far, and it did seem to help with star colour, the process was at first, frustrating as I had registered and integrated the images in App not pixinsight so it didn’t have any plate solve information, I had to then learn how to solve my image in pix and download the gaia catalogue and learn how to link it etc then I could recalibrate the image using my filter specific info.

It seems better to do this and remove the stars  whilst the image is linear, but it’s definitely worth a pop at doing it in its current stretched state just to see what you get!? 
 

I haven’t any examples on my phone to share sorry. 
 

let me know if it makes any difference? 
 

Cheers 

Bryan 

[assouptro]

Hi, Richard.

Actually, I think this was the image I was experimenting with, I’m not completely happy with it but I’ll share it anyway so you can see the star colour

Thanks 

Bryan

Edited October 24, 2023 by assouptro
Repetition!

[Lee_P]

15 hours ago, Richard_ said:

Boom. Love it!