M31 Andromeda in Ha...
 
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M31 Andromeda in HaRGB | 2 Pane Panorama


(@gideon96)
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ce5716d0 8b5d 46ea 838e 54a02420d2e3

https://www.astrobin.com/vr4e4k/B/

M31 Andromeda Panorama in HaRGB | 2 Pane

Our largest sister galaxy, distanced 2.5 million L/Y away from Earth, is bright enough to be seen on a fairly dark night with the naked eye. Her name derives from the constellation in which we view it from Earth, Andromeda, the princess who became Perseus' wife, as told in Greek mythology.
The large galaxy is home to an estimate of a trillion stars, with a bright mass-filled center and spanning ~120,000 L/Y in diameter.

While it seems peaceful from afar, Andromeda is advancing toward our own Milky Way galaxy at a pace of around 110 Km per second, meaning the two will collide in about 4 trillion years and continue to do so for another 2 trillion years, until forming a new combined galaxy entirely.
The fate of our own solar system, our Sun and Earth, is unknown.

Shot on two nights/locations:
OSC(Broadband) - Har Ha'Negev - Bortle 3
Ha (Narrow band) - Mitzpe Mesua - Bortle 5

2 Panes OSC ~3.5 hrs each
2 Panes Ha ~4 hrs each

ZWO 2600MM/2600MC
iOptron GEM45
ASIAIR Pro (Plan Mode)
EAF+36 mm Filter Wheel
Chroma Ha 5nm

Stack/stitched in AstroPixel Processor, processed in Pixinsight, export via PS.

 

-------------------

 

Thinking yet about this work, think the Ha introduced a bit to much red to the BG...
Any comments would be greatly appreciated.
Did have also a bit of issues with stitching, due to some differences of frames, might need to restack...


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 ah
(@ah_astro)
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Posted by: @gideon96

think the Ha introduced a bit to much red to the BG...
Any comments would be greatly appreciated

On my macbook it's the opposite. When I correct the background with +2% green and -2% blue (Affinity Photo) the background is a bit closer to neutral. Also the background appears to be differently corrected around M110 (less blue vertical bar?), but that could be due to the stitching and background correction.

I like that the background is not completely pulled to the black. Stars, dust and colours look great.


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(@gideon96)
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@ah_astro Thanks!

Yeah, I need to re-stitch the Ha panes, they are the culprit, I think...
DBE didn't solve the difference there, guess I need to change the LNC settings.

 

I will work more on it, thanks again for the comments, AH 🙂


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(@wvreeven)
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Posted by: @gideon96

DBE didn't solve the difference there, guess I need to change the LNC settings.

Have you tried the light pollution tool in APP?


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(@gideon96)
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@wvreeven 
Hey Wouter, not yet, but I think the problem was in the integration part, not afterwards, the stitching of the Ha panes together.

The stitch on the OSC panes was very balanced though one of the panes was lower than the second, also with higher lp in the distance (bortle 3 still).

 

I will give this another go, it's a shame to not process this image to its fullest...


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(@gideon96)
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When I get back home I'll post some examples from what I got.


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(@gideon96)
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I have over stretched it so it can be seen, that area between left and right, and in the middle there's obviously more data:

image
image

@wvreeven 

This is LNC 2nd degree, 3 iterations, MBB 15%


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 ah
(@ah_astro)
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Like Wouter suggested, light pollution correction may correct the background a lot...


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(@gideon96)
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Even after better LNC, that region is still "troublesome", the diff is clearly showing - but I'll have to rework the HA layer to see to which effect it will show on the red channel

image

 

Best I could do with DBE

image

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(@wvreeven)
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@gideon96 It looks like there is quite a large difference between the left and right Ha panel backgrounds. You may need to process them separately, apply light pollution correction on them and then stitch them together. It is cases like this that are hard to solve otherwise.


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(@gideon96)
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@wvreeven 

Yeap, I think it is unavoidable... Maybe on the osc as well.

 

I will give it a try.

 

 


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(@gideon96)
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Maybe a few more tweaks to OSC (bottom) but I think it looks much better in terms of gradients...

I dealt with LP before stitching, than stitched the panes and changed LNC settings, finally DBE in PI

image

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(@gideon96)
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No matter what I tried there are differences between sides.

image

My only suspicion is the balance between panes, In both OSC/HA I had one side with more data integrated.

image

 


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 ah
(@ah_astro)
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The background does seem to be more even now.


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(@gideon96)
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04 HaRGB Revision3 web

Ok..., soooo:

At the end, PS did the trick, a few masks and some color balance layers, and it looks much much better now.

https://www.astrobin.com/vr4e4k/C/


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