Cat's Eye Nebula NG...
 
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9 July 2020 - APP 1.082 has been released which contains one important bug fix. 1.082 has full Fujifilm RAF support, so that includes SuperCCD & X-Trans camera's 🙂 !

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Cat's Eye Nebula NGC 6543  

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(@maxthebuilder)
Molecular Cloud Customer
Joined: 2 years ago
Posts: 4
May 27, 2020 10:19  

Hello,

I am trying to shoot the Cat's Eye Nebula (NGC 6543) from my Bortle 9 location.

This is a difficult target as it has a very bright core and a very dim outer ring.

The outer ring gives me no problems. I shot a sequence of 360 sec subs and the ring came out nicely.

The core, of course, was way overexposed.

At 60 sec it was still overexposed.

At 30 sec it was OK (42000 out of 65532 levels).

At 15 sec it was well underexposed (21000 out of 65532).

Now. If I stack 15 sec exposures in APP I get blown-out/overexposed core.

If I save un-stretched to tiff and stretch in Photoshop I can get reasonable result. But I cannot stretch properly in APP. No matter what I do the core is blown...

 

Any suggestions?

Thanks!

 

Max


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(@astrogee)
Red Giant Customer
Joined: 2 years ago
Posts: 98
May 27, 2020 14:49  

I'm curious about this problem because stacking is supposed to average the image over the stacked amount of frames. So why does the output end up being almost indiscernible or in your case overexposed.


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(@vincent-mod)
Quasar Admin
Joined: 3 years ago
Posts: 1913
May 28, 2020 12:33  

This would require an HDR processing, APP doesn't have this (yet). I would then take long exposures for the faint signal and shorter for the bright parts. HDR processing can then be used to combine that nicely, I did that in PI and I guess Photoshop would also be possible to some extent (I have no experience with that).


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(@maxthebuilder)
Molecular Cloud Customer
Joined: 2 years ago
Posts: 4
May 31, 2020 02:04  

Ah.. OK. I just thought APP might help to equalize somehow.

My scope is too small to resolve any details in the core anyway..

Thanks!


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