Andromeda

[Space Oddities]

2x1 Mosaic, ~75x180s for each panel, gain of 100 and -10°C. Askar 80PHQ, ZWO ASI2600MC Pro, Rainbow Astro RST-133, ZWO ASIAIR Plus. Processed with PixInsight

 

This is a mosaic of the Andromeda Galaxy, with data captured over 2 consecutive nights early October. A project I've had in mind for a long time!

It was a challenging one:

• My mount experienced guiding errors, mostly the first night. The RA axis seemed to go nuts periodically and I had to throw away about 25% of the subs. I switched back from the OAG to a 50mm guide scope, and the problem seemed to go away for some reason...
• Strong gradients from Nantes' light pollition, as well as the last quarter of the Moon
• Colors and gradients for the 2 panels were slightly different, which makes creatig a mosaic more difficult. After a few attempts though, and with the help of some tutorials, I managed to find the right settings
• Blowing up the core of the galaxy while stretching is easy. I tried a new approach for stretching: 1) a slight stretch with ArcSinhStretch, 2) a Generalized Hyperbolic Stretch and 3) a few adjustments via curves & histogram. Lots of trial and error but overall the core doesn't seem too blown out!
• I finally switched from DeepSkyStacker to PixInsight for calibration and stacking. PI is so much slower... but the resulting image seemed easier to process, especially gradients, presumably due to the local normalization
• I'm still learning PixInsight, so every processing is a challenge! However I did learn a few helpful tricks, and I hope to remember them for my next processing.

But as always, despite the frustration and the hours spent working on this photo, I am very pleased with how it turned out! Definitely my best astrophoto so far.

Another reason why I love Andromeda, is because it was the first target I photographed when I started AP in 2017. I'll never forget the joy I felt seeing for the first time a galaxy on my camera's screen! It is always fun to measure the progress I've made over the years, and it definitely motivates me to keep on learning!

Critics more than welcome!

Clear skies!

Edited October 31, 2023 by Space Oddities

[nickp87]

Stunning captures.

I don't have my setup ready yet but I think Andromeda will be my first target if possible.  

[WolfieGlos]

I'm thinking about a Mosaic of M31 this winter, if our clouds ever clear. If mine is half as good, I'll be happy. Really nice image, well done!

6 hours ago, Space Oddities said:

Colors and gradients for the 2 panels were slightly different, which makes creatig a mosaic more difficult. After a few attempts though, and with the help of some tutorials, I managed to find the right settings

This intrigues me, and is something I'm currently struggling with a little on a different target. Do you have a link to the tutorials you used?

Edited October 31, 2023 by WolfieGlos

[sinbad40]

Wanted to go for this one for a while, with a small frame size it would need to be a multi panel, unfortunately either the weather is killing me or its in the wrong area of the sky 

Cracking image with good dust lanes.

 

[Paul M]

Thet's a nicely executed mosaic, and a proper screenfull of galaxy!

It gets my vote as image-of-the-day... so far

Edited October 31, 2023 by Paul M

[tomato]

Great mosaic, thanks for posting your first image, I remember the buzz I got from my first M31, even though it was just the core that was visible.

[windjammer]

That is a lovely image!

[JonHigh]

That is a fantastic image and well controlled core. Thanks for sharing your settings. 
Interesting to hear that an OAG helped your guiding issues. I have had some problems in guiding recently but put it down to awful atmospherics. Can’t see why I couldn’t try one out but it would be with a frac? I have also experienced the same colour issues doing a two panel mosaic. I found doing both panels in the same night then repeating over a couple of nights seemed to produce more consistent results. 

[ollypenrice]

Très belle galaxie! Balanced colour and brightness giving a natural look.

Olly

[MKHACHFE]

Stunning 

[Space Oddities]

Thank you everyone for the kind comments!  

 

On 31/10/2023 at 14:30, WolfieGlos said:

I'm thinking about a Mosaic of M31 this winter, if our clouds ever clear. If mine is half as good, I'll be happy. Really nice image, well done!

This intrigues me, and is something I'm currently struggling with a little on a different target. Do you have a link to the tutorials you used?

Well I have used 2 tutorials so far. The first one that gave me very good results on my narrowband data is this one : Creating a Mosaic image in 3 simple steps: PixInsight Mosaic Tutorial - YouTube

Here are 2x1 mosaics I made some time ago using Russell's great tutorial, as you can see it works seemlessly!

:

For some reason though, the settings used by Russell gave me good result with my narrowband images, but it didn't work well with this particular photo of Andromeda. I'm not sure why, but the result wasn't as seemless and smooth.

Then I found this other tutorial which uses the same tools but different settings, and the result was much better : EASY MOSAICS -- Part Two: Pixinsight Processing MADE EASY - YouTube

Perhaps one difference is that it was broadband OSC imaging on one side, and narrowband, black and white on the other side? Gradients are also different in both pictures, I'd need to play with the settings and see what's the best fit for each purpose.

 

On 31/10/2023 at 22:47, JonHigh said:

That is a fantastic image and well controlled core. Thanks for sharing your settings. 
Interesting to hear that an OAG helped your guiding issues. I have had some problems in guiding recently but put it down to awful atmospherics. Can’t see why I couldn’t try one out but it would be with a frac? I have also experienced the same colour issues doing a two panel mosaic. I found doing both panels in the same night then repeating over a couple of nights seemed to produce more consistent results. 

Thanks Jon! I actually thought the same and should have done the 2 panels on the same night. That's a good lesson for next time  

I actually had issues while using my OAG and that seemed to vanished with the classic 50mm guide scope. I hope this is user error and not my mount experiencing a hardware issue...

As you can see, the RA went nuts periodically and I could see the guide star drifting slowly. The mount would then try to counteract that movement. I tried other guide settings but it didn't really help. Usually the guiding is consistently below 0.5", so I'm not sure what caused this. 

[JonHigh]

Ah. Okay. Reread that! Just as well I didn’t buy an OAG! 😂 

I know the atmosphere has been really bad lately taking a serious toll on guiding to the point where I’m thinking what’s the point. 🙄. Mount and guide fighting each other!