Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Carole on Aug 11, 2018, 16:41:34

Title: Lion Nebula Sh2-132
Post by: Carole on Aug 11, 2018, 16:41:34
This was a particularly faint object, so even with the amount of data I had it was a struggle to process.
I used the dual rig but organised the cameras and scopes in such a way that the smallest FOV was in one and the largest in the other due to the planned targets being of unknown size.

I haven't as yet added the data from the smaller FOV so this could be a preliminary process, processed at DSC.

Taken over two nights and I cant say the 2nd night added much to the first night.

William Optics ZS71 & Atik460EX + FR x 0.8
Baader filters HOO
HEQ5
Ha 2 x 900 secs + 14 x 600 secs (2h 50 mins)
Oiii 1 x 600 secs (2h 30 mins)

Grand Total 5h 20m and a pig to process.

(https://cdn.astrobin.com/thumbs/BBAg4xsMIYB6_1824x0_wmhqkGbg.jpg)

Edit:

This was re-stacked and processed with a better result.

(https://cdn.astrobin.com/thumbs/DE7p8l_WHmtM_1824x0_JoKSVx0j.jpg)
Title: Re: Lion Nebula Sh2-132
Post by: MarkS on Aug 11, 2018, 20:44:13
I've never come across that one before Carole.  A very interesting looking object.

It has a lot of potential and I'm certainly looking forward to seeing the finished result.

Mark
Title: Re: Lion Nebula Sh2-132
Post by: The Thing on Aug 11, 2018, 21:28:56
Ditto what Mark said!
Title: Re: Lion Nebula Sh2-132
Post by: Carole on Aug 12, 2018, 08:59:29
OK, I stacked the Ha data from the Atik314L camera and I found the data to be much better.  The data from the Atik460EX camera in the image above was black clipped straight from the stacking, I have no idea why as the same settings were used for both, and this applied also to the Oiii data which I didn't take with the Atik314L.

So as the FOV was smaller I have made a much smaller crop of the Lion nebula using only the Ha from the Atik314L which was much more anyway as it ran Ha throughout, but had to use the clipped data for the Oiii from the Atik460EX as that's all I have.

So new details are (and I will put this in its own post as well).

Cairds campsite SQM 21.05

Ha - SWED80 & Atik314L 29 x 600secs + FR x0.8
Oiii - WOZS71 & Atik460EX 16 x 600 + FR x 0.8

Total imaging time 7 1/2 hours

HEQ5

(https://cdn.astrobin.com/thumbs/htES1E9v7g1-_1824x0_wmhqkGbg.jpg)

Title: Re: Lion Nebula Sh2-132
Post by: NoelC on Aug 13, 2018, 10:16:39
lovely image Carol
I far prefer the second one; can see the lion!
Title: Re: Lion Nebula Sh2-132
Post by: JohnP on Aug 13, 2018, 12:21:31
2nd much better - the processing on first is way too harsh - 2nd is a lot more subtle - good job.  John
Title: Re: Lion Nebula Sh2-132
Post by: Carole on Aug 13, 2018, 18:46:45
Thanks John and Noel.

I agree.

However there was something wrong with the Data from the Atik460EX camera which I can't explain as it was already black clipped straight from the stacking software, so not a lot I could do about that which was obviously what made the processing so difficult. 

The data from the Atik314L was stacked in exactly the same way with same settings, so no idea why the Atik460 data was black clipped and it has never
happened before.

Carole
Title: Re: Lion Nebula Sh2-132
Post by: Carole on Aug 13, 2018, 18:48:27
PS: I have left the original image in the first post so you can see the entire nebula as most of you seem unfamiliar with this target, and yes you can see the Lion.

Carole
Title: Re: Lion Nebula Sh2-132 Re-stacked and processed
Post by: Carole on Aug 15, 2018, 09:56:26
After some thought, I decided to re-stack the data for the full frame and this time tried leaving out the darks and it is no longer clipped, I think I used slightly unmatching darks when at camp, so lesson learnt.

So this is the new full frame process:

(https://cdn.astrobin.com/thumbs/DE7p8l_WHmtM_1824x0_JoKSVx0j.jpg)
Title: Re: Lion Nebula Sh2-132
Post by: The Thing on Aug 16, 2018, 08:56:19
It's looks much better Carol. Worth the effort.
Title: Re: Lion Nebula Sh2-132
Post by: Carole on Aug 16, 2018, 10:21:40
Thanks Duncan, I have still not combined both cameras, but at least I got the clipped data to stack and not be clipped.

Carole
Title: Re: Lion Nebula Sh2-132
Post by: MarkS on Aug 16, 2018, 20:02:18
Wow! That really is much better!

Very interesting nebula ...

Mark
Title: Re: Lion Nebula Sh2-132
Post by: Carole on Aug 16, 2018, 22:03:19
Thanks Mark, it does just go to show how clipped data can really stunt your processing and results, no wonder I thought it was such a pig to process at the beginning.

So leaving out darks made the difference, I did not have any matching ones in my library.

Carole