7 replies to this topic

[whiskeyzebra11]

It's been two months since I had clear skies, so I was delighted to have a clear evening this past weekend. I've never imaged M16 before, but I have seen some very colorful images from others, so decided to try to capture it with a dual narrowband filter. This is four hours of data. I found it very challenging to try to bring out any color other than the Ha in the stacked image. Tried many different pixel math combinations I found online, but I ended up going with strict HOO: R:100% Ha, G:100% Oiii, B:100% Oiii.

 

The resulting image still didn't have much color beyond the red in an autostretch, but after some initial GHS stretches, I did an inverse GHS stretch on the red channel to bring it more inline with the blue/green which brought out the blue/green significantly. Then played around with curves in Siril a bit and further GHS stretches. This was the best I could manage bouncing back and forth between Siril and Seti Astro Suite.

 

Clouds have set in so I'm unlikely to get much more data to add to this. Looking for any suggestions or tips on anything you see here that I could improve upon. I'm wishing the colors were richer or perhaps more saturated. Not sure if that simply requires more data or if there is some processing piece I'm missing. All acquisition/processing details below.

 

Thanks for looking.

 

 

 

link in gallery

4 hours dual narrowband (Svbony 220 filter)
60s subs @ 100 gain
darks/flats/darkflats applied
Skywatcher HEQ5-Pro
Askar 71F w .75x reducer
ZWO EAF
ASI533MC @ 0C
NINA
Phd2 guiding

 

Stacked in Siril with HaOIII extract script
BGE of Ha and Oiii images with Graxpert
Combined in Siril pixel math R: Ha, G: Oiii, B: Oiii
SPCC Color calibration
Cosmic Clarity Sharpening/Denoise
StarNet star removal
GHS/Curves in Siril
HDR/Curves adjustment with SetiAstroSuite
Star mask from separate Pixel Math combination using different weighting for green channel

[rlmxracer]

I think it looks real nice and not just for 4 hours. I have had similar results with my rig (similar to yours). 

[CalifDan]

Interesting.  Late last week I did two nights on M16 and just over 4 hours.  I'm limited to viewable sky so 4 hours for me is two nights.

 

Edit:  Sorry, I didn't quite finish.  I will have to explore what you did with Pixel Math.  That is interesting.  I used an Optalong Dual Band for all of my images.

Attached Thumbnails

• 

Edited by CalifDan, 23 June 2025 - 08:25 PM.

[rj144]

I have a Triband filter, not a dual band, but I do something completely different in Siril.  

 

I use manual color calibration and just calibrate the background which brings out the Ha.  I do deconvolution and run Starnett.

 

Then on the starless image, I calibrate the background again and highlight a huge portion of Ha and do the white balance in manual color calibration on that selection.  That gives a lot of blues, magentas, and greens (I like a little green mixed in with the nebula).  I process both images fully and blend the blue into the Ha a bit in Affinity.

 

I normally don't post pics in others threads, but just to show:

 

 

There was more colors too if I wanted, but I blend to taste.

 

That was about 5 hours from Bortle 8/9.

Edited by rj144, 23 June 2025 - 09:07 PM.

[Spaceman 56]

I'm wishing the colors were richer or perhaps more saturated. 

hi Whisky.

 

Affinity photos can easily add saturation. many other photo editors can do it too.

 

 

unsure if this is what you were thinking ?

 

I just added a subtle boost.  

Edited by Spaceman 56, 23 June 2025 - 11:41 PM.

[Spaceman 56]

Or go wild like this if you want.

 

 

Kind of Loud.  

 

 

 

 

[whiskeyzebra11]

I have a Triband filter, not a dual band, but I do something completely different in Siril.

I use manual color calibration and just calibrate the background which brings out the Ha. I do deconvolution and run Starnett.

Then on the starless image, I calibrate the background again and highlight a huge portion of Ha and do the white balance in manual color calibration on that selection. That gives a lot of blues, magentas, and greens (I like a little green mixed in with the nebula). I process both images fully and blend the blue into the Ha a bit in Affinity.

I normally don't post pics in others threads, but just to show:



There was more colors too if I wanted, but I blend to taste.

That was about 5 hours from Bortle 8/9.

That manual color calibration definitely made a difference in bringing out the colors. Thanks for that suggestion. Need to re-process this fully now and see if I can get an overall improvement.

[Drothgeb]

I’ve processed it a few different ways, and thought the SHO palette worked best.