Lagoon with patience

[kosborn]

Hi all,

Last night at last relief from the clouds. The Lagoon nebula was in my sights and with no moon I thought LRGB was the way to go. Lots of integration time and didn't finish until 4am but in the end I'm happy with the result. I collected an hour of Ha as well hoping to add that to luminance and red channel but in the end I left it out. I'd really like to hear how people add Ha to LRGB images. This is 50x 120s luminance and 25x 120s each of red, green and blue for a total of 4.2 hours. A higher res version is at https://www.astrobin.com/full/350785/0/?nc=user

Kevin

[xelasnave]

Kevin I cant help with your request for help but may I say that is a wonderful image. Well done.
Alex

[ZeroID]

Well done, very nice image. Wish I could manage to stay up that long.

Like yourself I'm still trying to figure out the best way to add Ha to mono. I suspect if you added it to the Red channel you may find a lot more diffuse glow around the central nebula but I find sometimes it adds too much and loses the definition. Still experimenting...

[Atmos]

It's sharp, great colour and resolution!

What software are you using for processing? I've never used anything but PixInsight so that's all I know :)

[kosborn]

Thanks Alex and Brent. Much appreciated.







Thanks Colin. This was all PixInsight from calibration and stacking to completion. I tried adding Ha to the red channel in variations from 10% to 30% but all it seemed to do was make the core redder and what I like about the version I ended up with is the contrast between the core and the outer parts of the nebulosity. I was also going to add about 20% of Ha to the luminance but with nearly 2 hours of luminance I already had nice coverage of the fainter parts of nebulosity.


I think instead I'll save the Ha data for a run of narrowband when the moon is out next.


Kevin

[Atmos]

What I have found best personally is to first use LinearFit. Use your red frame as the reference and use it on the Ha.

Then go into PixelMath and create a master red with:
Max(R,Ha)

This will add the Ha into the red channel and as it has been fitted against the red channel it should help with the blowout.

[Mickoid]

Amazing detail you've picked up there Kevin. Aren't these SW Esprit's great scopes? On my Canon 550d I can manage a wider field than your ccd camera can using this scope but your result is a much zoomed in view of the Lagoon. This capture has just shown how good these scopes are and the Ccd camera has taken full advantage of the Esprit's optics. A lovely effort under these cold winter skies, your 4 hrs of integration has paid off with this one, well done! :thumbsup:

[kosborn]

Thanks Michael. Yes the Esprit 100 is a great scope, really sharp optics and with the field flattener round stars right to the edges, even with a full frame sensor I'm told. Your sensor would certainly give a larger field than mine but I've also used a bit of judicious cropping. ;)






That makes sense. I'll certainly give that a go. Thanks.


Kevin

[RickS]

Nice work, Kevin!

The NBRGBCombination script in PI is worth a go. I sometimes like the results it produces and sometimes not :) I have half a dozen different techniques for adding Ha to RGB images and I usually try a few and pick what I like for each different image.

Cheers,
Rick.