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My first attempt at M31 - Andromeda Galaxy

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#1 Jireh

Jireh

    Mariner 2

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Posted 09 October 2019 - 05:11 PM

I was able to get out and get a few hours of M31 data. After getting used to my ES127 and Esprit 100 I found it very difficult to focus with the DSLR lens. But it was my only option for capturing M31 other than doing a mosaic.

 

I'm a little disappointed in the detail and color balance. I want to try again but I'm not sure when I'll get a chance. CC welcome!

 

Canon 70-200 f/2.8 DSLR Lens

Astromechanics Canon Lens Controller Mark II

Sky-Watcher EQ6R Pro Equatorial Mount

ZWO ASI1600MM Pro w/EFW

ZWO ASI290MM Mini Guide Camera

Orion Mini 50 mm Guide Scope

QHY PoleMaster

SGPro, PHD2

 

85x30s L, 40x30s R, 40x30s G, 40x30s B

 

DSS, processed in Photoshop

 

m31.jpg


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#2 klaussius

klaussius

    Sputnik

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Posted 09 October 2019 - 05:59 PM

You seem to have what it looks like field rotation.

 

Given your tracking setup, and the fact that I can't really pinpoint where the rotation center would be, I suspect it could instead be geometric distortion from the lens. Which looks similar, but it's something else - an aberration coming from the lens itself.

 

You should try to correct geometric distortion on each of your subs before stacking. I'm not sure, but I don't think DSS has that functionality. If you can do it with raw editing software and save raw tiff, that might work.

 

I'm actually working on incorporating lensfun, a lib that does that, into my own custom stacking software, because I have the same issue with a few wide-angle shots I took a while back.


Edited by klaussius, 09 October 2019 - 05:59 PM.


#3 Alen K

Alen K

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Posted 09 October 2019 - 08:51 PM

You should try to correct geometric distortion on each of your subs before stacking. I'm not sure, but I don't think DSS has that functionality. If you can do it with raw editing software and save raw tiff, that might work.

The OP might want to try Sequator for stacking. It can compensate for geometric distortion when aligning the stack. It is Windows only, however. 



#4 TelescopeGreg

TelescopeGreg

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Posted 10 October 2019 - 12:04 AM

The OP might want to try Sequator for stacking. It can compensate for geometric distortion when aligning the stack. It is Windows only, however. 

I find Sequator runs on my Linux system very well under Wine. 


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#5 Alen K

Alen K

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Posted 10 October 2019 - 12:51 AM

I find Sequator runs on my Linux system very well under Wine. 

That's great to know but it doesn't change the fact that Sequator is a Windows application.




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