Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: The Thing on Oct 08, 2019, 12:37:12

Title: LBN437/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: The Thing on Oct 08, 2019, 12:37:12
It is LBN 437 - my lysdexic tendency coming out ;) Carole is correct.

A very interesting bit of the sky, this dark nebula has a lot going on around it. Still learning a lot about PixInsight and I think I've made progress. The sky was very variable and I had to discard half the subs.

23x240s OSC, Gain 120 (unity), Offset 8, Temp-15c.

Telescope aperture and focal ratio:   TS1506UNC f4, TS Komakorr
Camera and filters used:   ZWO ASI294MC Pro, Baader Neodymnium 1.25" filter
Processing applied:   Pixinsight

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/normal_light_BINNING_1_integration_clone_ABE.jpg) (http://gallery.orpington-astronomy.org.uk/albums/userpics/10050/light_BINNING_1_integration_clone_ABE.jpg)
Title: Re: LBN473/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: Carole on Oct 08, 2019, 12:57:49
So that's where every-one has been, thought it was exceptionally quiet on the forum.

I tried to look up that Nebula as I had not heard of it and of the few I could find it seems to be listed as LBN437 - also apparently known as the Gecko nebula with swathes of Ha which you have captured.

Looks very faint - a brave choice for a OSC camera.  But you have got a fair amount of detail out of it.

CC:  I'd say it is a little green, could do with - is it SNCR in Pixinsight?. (HLVG in PS)  Bottom right stars a bit too orange. Overall I'd say a very good effort.

As you say a very interesting bit of the sky, I have a few other potential images lined up for that area.  Of course all needing a dark location.

Carole

Title: Re: LBN437/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: The Thing on Oct 08, 2019, 13:11:28
Thanks Carole, I am amazed at what I got with so little data. It's had no darks, only flats and flat darks. For some reason whatever I do my darks just aren't dark at the moment, a mystery to be solved.

It's had Photometric Colour Callibration applied which looks up the colours of all the stars online and SNCR applied to reduce green (well remembered Carole) and my new IPS laptop screen has been calibrated with a Spyder. Also I'm a bit blue/green colour blind so it looks just fine to me. I'm more bothered by the slight dark rings around stars and posterisation that is apparent in some areas. I wouldn't notice these things if Robert hadn't been saying "I wouldn't accept that" and "that wouldn't be good enough for me" every time I tried a process! But he has been a great help.
Title: Re: LBN437/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: NoelC on Oct 09, 2019, 10:08:25
Looks pretty amazing to me!
(I'm slightly red/green deficient).

Noel
Title: Re: LBN437/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: RobertM on Oct 09, 2019, 10:14:32
Nice one Duncan.

Just one thing - something looks a bit awry.  Did you use DBE ?

Robert
Title: Re: LBN437/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: The Thing on Oct 09, 2019, 10:27:21
Quote from: RobertM on Oct 09, 2019, 10:14:32
Nice one Duncan.

Just one thing - something looks a bit awry.  Did you use DBE ?

Robert

I used ABE and tuned it to leave most of the Ha.
Title: Re: LBN437/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: The Thing on Oct 09, 2019, 10:27:56
Thanks Noel. It's quite busy.
Title: Re: LBN437/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: The Thing on Oct 09, 2019, 10:33:44
This is a really nice version of this object (https://delsaert.files.wordpress.com/2019/08/lbn442_mosaic_lhargb.jpg) - I should have looked at this to get some idea of what to aim for. I seem to have more dust and less Ha, and I have vastly less data.

(https://delsaert.files.wordpress.com/2019/08/lbn442_mosaic_lhargb.jpg)
Title: Re: LBN437/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: RobertM on Oct 09, 2019, 11:07:40
Quote from: RobertM on Oct 09, 2019, 10:14:32
Nice one Duncan.

Just one thing - something looks a bit awry.  Did you use DBE ?

Robert
That explains it.  I think it's also brought out a greenish cast.

Robert
Title: Re: LBN437/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: Roberto on Oct 09, 2019, 14:28:52
Well done Duncan!  8)  This is a difficult object and yes, it should look much more reddish as Ha overwhelms other emissions. 
This is my version from a couple of years ago:  https://www.astrobin.com/310671/F/

Roberto
Title: Re: LBN437/DG 187 in Cepheus, Astrofarm, Oct 2019
Post by: MarkS on Oct 11, 2019, 20:32:17
Nice one!

There's a lot going on in that image, what with the dust and H-alpha.

I agree with Robert that overall it looks a bit too green.  Also, in my experience DBE is very difficult to use on such images because there is very little clear background on which to place the sample points.

Mark