Sh2-86 in Ha

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oopfan
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Sh2-86 in Ha

Post by oopfan »

Only 2.3 hours, but it's a start. OIII and SII are almost non-existent, so I'll have to make do with only Ha:
Sh2-86_Ha-7nm-14x600s-b1_APP-star-reduction_AFF-brightest-EX96.jpg
Sh2-86_Ha-7nm-14x600s-b1_APP-star-reduction_AFF-brightest-EX96.jpg (992.86 KiB) Viewed 269 times
Here is a slide I prepared to show what steps were involved:
Sh2-86_compare.jpg
Sh2-86_compare.jpg (969.86 KiB) Viewed 269 times
Brian
timh
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Re: Sh2-86 in Ha

Post by timh »

That is an interesting object Brian. It wasn't even on my radar to look at. You could perhaps try in RGB and adding the HA signal into the luminance as an alternative route to color? That work flow was good for for me on other HA only objects (like the flaming star nebula in Auriga) - although I appreciate it is a lot more work. While you are taking 10 minute subs I have reverted to the other extreme and am currently processing thousands of very short subs to see if I can get any further with speckle type imaging --.

TimH
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oopfan
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Re: Sh2-86 in Ha

Post by oopfan »

Thanks, Tim. Sh2-86 could be a real stunner with more integration time. Probably needs at least 10 hours in Ha alone. This is the price I pay for imaging narrowband using bin mode 1. The weather is largely uncooperative again. I squeezed in two nights this past weekend. Now I wish I didn't waste that first night on M57. My scope isn't good with small objects, but I had to learn the hard way!

Brian
timh
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Re: Sh2-86 in Ha

Post by timh »

Exactly the opposite case for me :-) -- I have been concentrating only on M57 using my old 10 inch Dobsonian because it is an object that plays to the strengths of that sort of scope. Plus also I rather like the idea doing more on lucky imaging and exploring what is possible with just the minimal set up of AltAz Dob plus an uncooled small chip sized camera....and of course Sharpcap. At 51 degrees N it never gets dark this time of year so a good time to mess about with that sort of project.
Tim
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oopfan
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Re: Sh2-86 in Ha

Post by oopfan »

Thanks to everyone for making me top of the leader board!

Last night I picked up another 2.6 hours in Ha, for a total of nearly 5 hours. I'm debating whether to add one more session. I was very pleased with my M27 in Ha and OIII. That was a total of 6.4 hours. The noise content in the outer shell was quite low.

Next step is to capture RGB to add some natural color. I have zero experience with that technique. A few weeks ago, I tried adding RGB to M27, but I lost a lot of the outer shell. That was using Astro Pixel Processor. Then, I tried Affinity Photo to mix it. It did a better job, but I still lost some of the outer shell. I don't want to give up anything!

Any suggestions will be greatly appreciated.

I posted a question at the APP forum that explained my problem. I received a reply that confirmed my understanding that APP's algorithms expect linear data. APP does allow you to stretch the image while you work on it, but that is only for visualization. The final step an APP user goes through is saving the stretch to a file. The purpose is to open it in other post-processing software like Photoshop or Affinity Photo. According to a person who replied to my post, the reason why I lose M27's outer shell is due to the higher noise content of the RGB data. Think of it like this: I have Bortle 5 skies, but when I use a narrowband filter, I am magically transported to Bortle 3 skies (just making that up!) So, I am trying to mix RGB data from Bortle 5 with NB data from Bortle 3. So, the Bortle 5 data will always be noisier.

So now I am thinking that the way around this problem is to apply copious amounts of noise reduction to the RGB image using Affinity Photo before mixing in the NB image data.

Brian
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oopfan
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Re: Sh2-86 in Ha

Post by oopfan »

Last night I picked up another session of Ha. Here is the result. This time no false color and a little less star size reduction. A definite improvement, but now I can see why people put in 20 hours! So, the next clear night, I am going to concentrate on picking up RGB in an effort to inject some natural color into those stars and the nebula.

Brian
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Sh2-86_Ha-7nm-31x600s-b1.jpg
Sh2-86_Ha-7nm-31x600s-b1.jpg (940.7 KiB) Viewed 155 times
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turfpit
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Re: Sh2-86 in Ha

Post by turfpit »

Brian

Longer integration is certainly bringing improvement. The star reduction seems to be doing a good job.

Dave
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oopfan
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Re: Sh2-86 in Ha

Post by oopfan »

Dave,

Yes, the brightest star in the cluster (center frame) is magnitude 9.3. It merges with neighboring stars into an unsightly mess when stretched. APP's star size reduction operates on the unstretched image, so it is able to isolate the stars and reduce them beforehand.

Brian
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Menno555
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Re: Sh2-86 in Ha

Post by Menno555 »

The grayscale version looks awesome! :!:
And yes, integration time can do a lot, depending on the object.

Menno
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Re: Sh2-86 in Ha

Post by oopfan »

Thanks, Menno. Still a lot of noise, but it is getting better. I might get a 2-hour window tonight to pick up some color.

Brian
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