Fixing scattered light issue [Deep Sky] Processing techniques · Jure Menart · ... · 9 · 315 · 4

This topic contains a poll.
What should poor Menart do next?
CloneStamp rules!
Rotate camera for 180°
Find the source of scattered light and try to fix it
Slightly change position / rotation
Other ideas (please leave a comment)
Throw it away and get a real hobby
jmenart 2.15
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Hi all

After few days of Ha & Oiii acquisitions I finally checked my result. And of course as always I found an issue on integrated images I have quite nasty scattered light in right top corner. Of course it's on both images so I don't have good reference to use @Adam Block trick to replace part of the image

I couldn't find the guilty star (I assume it's a star and not reflections from nearby light sources - as my previous project was not far away on the sky and I didn't see this issue at all).

Lucky my acquisition is not done yet (I think I am somewhere in the 50% of acquisition), so I see few options:
  1. At the end simply use CloneStamp and remove it carefully and leave acquisitions as they are now
  2. Rotate camera for 180° - I might have scattered light on both corners but also some good reference to fix it with replacement (it's corner of the image and not the main focus of the image, so I could get away with slightly higher noise I think), bad thing is I double the issue in both corners
  3. Do the right thing and investigate why this reflection and fix it - I will be honest, the nights are so short, I'd like to avoid doing this and just continue with my calibrated setup through this project The lazy way I know
  4. Slightly change position / rotation and try to get rid of scatter light and not loose too much final FOV - problem I see with this is that the scattered light is not visible in single subs, so I am not sure if I wouldn't just make it worse and loose final FOV
  5. Other processing or acquisition ideas?
  6. Throw subs away and get a real hobby


Ha and Oiii integrated images (GraXpert quick background extraction, StarXTerminator & STF applied for easier visibility of the issue):
image.png
image.png
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messierman3000 7.22
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that little thing in the corner?

just crop like this when you're done getting all the data:
rere.jpg
it'll still look great.
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jmenart 2.15
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Oscar:
that little thing in the corner?

just crop like this when you're done getting all the data:
rere.jpg
it'll still look great.

Hi Oscar

Thanks!

I intentionally left out cropping which of course it's valid solution But I agree I might do that at the end, so in this case it's better to just continue with the same acquisitions.

I want to see some ideas of fixing this issues as it's often the problem with our pictures.
Edited ...
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andreatax 9.89
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The practical thing to do is to wait for the crossing of the meridian and the thing will likely disappear (crossing fingers here). You would then have a clean (at least locally) image to use to clone-stamp the reflection away.
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ams.astrophotography 1.20
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andrea tasselli:
The practical thing to do is to wait for the crossing of the meridian and the thing will likely disappear (crossing fingers here). You would then have a clean (at least locally) image to use to clone-stamp the reflection away.

I have the same problem with my reflector.  I'm wondering why crossing the meridian would resolve it?  Wouldn't it just appear in the diagonally opposite corner?
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jmenart 2.15
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andrea tasselli:
The practical thing to do is to wait for the crossing of the meridian and the thing will likely disappear (crossing fingers here). You would then have a clean (at least locally) image to use to clone-stamp the reflection away.

Wouldn't that be basically.the same as 180 degree rotation? Unfortunately at this moment meridian flip happens after the astronomical darkness.
I have the same problem with my reflector.  I'm wondering why crossing the meridian would resolve it?  Wouldn't it just appear in the diagonally opposite corner?

Yes it would appear at opposite corner which means real signal would be stronger then scattered light. And even if not one could use only integration without scattered light for each corner.
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andreatax 9.89
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Jure Menart:
Wouldn't that be basically.the same as 180 degree rotation? Unfortunately at this moment meridian flip happens after the astronomical darkness.


Then you're all good. Or you meant after the astronomical darkness is over? You still have about an hour of nautical darkness which is fine with NB imagining.
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andreatax 9.89
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Anne-Maree McComb:
I have the same problem with my reflector.  I'm wondering why crossing the meridian would resolve it?  Wouldn't it just appear in the diagonally opposite corner?


Yes, that is exactly. You can either average them or, better, clone stamp the affected areas with the image that isn't affected.
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SteveInColorado 1.43
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andrea tasselli:
Jure Menart:
Wouldn't that be basically.the same as 180 degree rotation? Unfortunately at this moment meridian flip happens after the astronomical darkness.


Then you're all good. Or you meant after the astronomical darkness is over? You still have about an hour of nautical darkness which is fine with NB imagining.

Is nautical darkness OK for OIII data?  I’ve always done H-alpha during that period.
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andreatax 9.89
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Steve:
Is nautical darkness OK for OIII data?  I’ve always done H-alpha during that period.


*Yes, but not as good as during the astronomical night.
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