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Barking up the wrong Nebula ?

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#1 limeyx

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Posted 29 September 2020 - 12:54 AM

Hey folks, I am wondering if I have something fundamentally wrong with my setup, or if I am just being too ambitious and should just stick to making 52 images of M31 or the Moon every year

 

I know my mount is not that great for DSO (Skyguider Pro) and I have a DSLR lens and camera, but I figured I should be able to see SOME sign of nebulosity

 

I took on the Wizard on Sunday. Unfortunately a broken USB cable and some focus issues limited the subs I could take, but I would have thought that a 180 second sub at f/4.5 ISO 200 would show *some* hint of nebulosity, but I see ... just stars in a variety of focus

 

This is an unstretched light I understand I need to stack to get a good signal but each sub should add something right? Even stretched I really don't see anything here. Even if I do 30 sec at ISO3200 I still don't really see anything

 

https://drive.google...iew?usp=sharing

 

I do see this pattern when I zoom in Pixinsight with the new lens I am using. I do see something like it with the old cheap zoom lens but it appears to be a lot less.

 

I figure I should be able to get *some* results on these targets even if they aren't wall-hangers.

I am going to go over my setup and take it down to the single parts and reconfigure and re-setup everything, including camera.

I suppose it could be bad data transfer from the dodgy cable that finally failed but that seems a bit far fetched

 

Attached Thumbnails

  • WeirdPattern.png


#2 Complexmystery

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Posted 29 September 2020 - 01:10 AM

You did manage to capture it. 

 

https://nova.astrome...34862#annotated

 

I will say that even with more advanced equipment that the Wizard is a difficult target. I too would like to revisit this nebula as last years attempt left me wanting more in terms of signal. With a 300s Ha image with an STT-8300 and C11 reduced to f/6.3, I barely picked up anything. 


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#3 Euripides

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Posted 29 September 2020 - 01:11 AM

First of all your mount is capable to achieve DSO targets easily, so you are good to go :-)

 

Your image lies here in the sky, so you are dead center my friend :-) (Because you are not plate solving, nova.astrometry.net is your friend)

 

4600715.jpg

 

Unfortunately it will take multiple shots to even see a bit of nebulosity. Always it depends from your target (M31, Orion Nebula are much brighter and you have visibility from 1st shot) and of course from your location (light pollution, filter you use to counter this).

 

 

 

 


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#4 RJF-Astro

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Posted 29 September 2020 - 01:17 AM

Yes it is a more difficult target. The data is probably there so if you stack multiple hours you will start to see something. But this is where narrowband really shines.

There are easier targets besides M31, like NGC7000, Cygnus loop, M45, M27 etc.

 

By the way: that pattern you see is the bayer array. You need to debayer in PixInsight first.


Edited by RJF-Astro, 29 September 2020 - 01:19 AM.

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#5 pyrasanth

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Posted 29 September 2020 - 02:02 AM

One last tip- very faint targets will need good image calibration. You will not see much until the bias and dark noise is removed from the image as well as the use of flats. This will make a very big difference on faint targets as you want to be able to stretch the signal and not lose that signal in the sensor noise.



#6 limeyx

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Posted 29 September 2020 - 10:35 AM

Thanks everyone. I was using plate solving (which is a miracle!) so I knew I was on it Unfortunately with the SGP mount I am not sure how accurately I can line up the same place night on night, although since its fairly small in the frame, I have room to crop

 

RJF - good call on the bayer. I am used to raw images, but not ones pre-debayer so that makes total sense !

 

I will try M27 even though it is also small. I am avoiding M31 a bit because it seems like a pretty different kind of target and I want to see if I can caputure one of these dimmer ones. If not, then I will just back off

 

Thanks for the advice !




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