Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: MarkS on Oct 15, 2014, 00:03:11

Title: Pacman Nebula in September
Post by: MarkS on Oct 15, 2014, 00:03:11
Pacman Nebula taken over 4 nights in September, including Kelling Heath.

17 hours of data in 5 minute subs at ISO 800.
Modified Canon 350D on Tak Epsilon 180ED with IDAS LPS-D1 filter

(http://www.markshelley.co.uk/Astronomy/2014/pacman30092014small.jpg)

My intention was to capture the dust in the surrounding area but it was a real pig to process.  There is much more that can potentially be brought out of the data to emphasize the dust but every time I tried to do so, the Pacman Nebula itself looked horrible, so this is my best compromise.

It looks better in the larger size:
http://www.markshelley.co.uk/Astronomy/2014/pacman30092014.jpg

In the bottom right of the larger image I've managed to chop off an small interesting looking reflection nebula.

The Pacman itself actually looks much better in mono, with just the red channel data.  With the green and blue channels included, it loses an awful lot of contrast.

Mark

Title: Re: Pacman Nebula in September
Post by: Carole on Oct 15, 2014, 09:46:32
17 hours Mark - Phew - great work!!

I always admire your star colours.

Carole

Title: Re: Pacman Nebula in September
Post by: The Thing on Oct 15, 2014, 12:04:41
Thats quite something, there is loads of faint red dust in patches quite a long way out from the main body of Mr Pacman. Maybe it needs a version processed for the Pacman and a version processed for the dust and then merged. 

And the reflection nebula does look interesting.
Title: Re: Pacman Nebula in September
Post by: mickw on Oct 15, 2014, 12:18:47
Nice one Mark
Title: Re: Pacman Nebula in September
Post by: Fay on Oct 15, 2014, 13:48:15
well done mark, so many stars and lovely colours!!
Title: Re: Pacman Nebula in September
Post by: JohnP on Oct 15, 2014, 15:53:50
Looks good mark & great colours. Like you said the Pacman itself looks a little diffuse - I would so love to have seen the result you would have got with your setup using 17hrs & a dedicated B&W camera...

John
Title: Re: Pacman Nebula in September
Post by: MarkS on Oct 15, 2014, 22:03:10
Thanks all.  This one definitely needs a full re-process and I think I may have thought of a way to tackle it ...
Title: Re: Pacman Nebula in September
Post by: julian on Oct 15, 2014, 23:30:02
Very nice, like the colours and details in the image
Title: Re: Pacman Nebula in September
Post by: MarkS on Oct 19, 2014, 00:51:40
Here's the full re-process.
The dust has come out better and I've just about managed to keep the star bloat under control.

(http://www.markshelley.co.uk/Astronomy/2014/pacman30092014v2small.jpg) 

Bigger version:
http://www.markshelley.co.uk/Astronomy/2014/pacman30092014v2.jpg

Mark



Title: Re: Pacman Nebula in September
Post by: Fay on Oct 19, 2014, 08:34:20
I really like that Mark, nice and subtle, great star colours
Title: Re: Pacman Nebula in September
Post by: The Thing on Oct 19, 2014, 11:25:07
Amazing. Next Astronomy Now cover or there's no justice.

It just goes to show how much of the result is down to processing once you have acquired good data and how pernickity it can be to get the right combination of adjustments and settings to get such different results.
Title: Re: Pacman Nebula in September
Post by: Carole on Oct 19, 2014, 11:38:10
I agree Duncan, processing is half the battle, but you need some decent data to start with, as Mark's is.

Beautiful image Mark.

Carole
Title: Re: Pacman Nebula in September
Post by: mickw on Oct 19, 2014, 18:12:10
Real good Mark and better star colour
Title: Re: Pacman Nebula in September
Post by: MarkS on Oct 19, 2014, 23:40:08
I've just found this version:
http://www.starpointing.com/ccd/ngc281.html

It's the best colour version of the Pacman I've ever seen - 31 hours of data with very decent equipment.  Now I'm very depressed :(

Interestingly, he has rendered his surrounding dust as whitish/grey.  I've seen that trick before and it's probably because the chrominance was too noisy.

Mark
Title: Re: Pacman Nebula in September
Post by: RobertM on Oct 21, 2014, 14:59:39
Oh dear !  That'll teach you - never look for a better version no matter how good yours is (or stock up with beer beforehand) !

Very good reprocess indeed !

Robert