Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: JohnP on Feb 15, 2008, 11:20:13

Title: M81 - I'm pleased with this....
Post by: JohnP on Feb 15, 2008, 11:20:13
Hi All,

I have been working in Birmingham this week & rather stay in some grotty hotel I decided to stay at my Mother's (lives in North Oxfordshire) - Anyway before leaving Monday night I had a quick look at forecast & it was looking good for Tues/ Wed - So early Tues morning (4.30am) I made the effort to throw all the astro gear in the car. The skies where my mother lives are similar to Tuesnoad...

Tues night was clear (although threatening mist/ fog) - I had a lot of guiding probs early on but sorted this out & eventually got to take about 90mins worth of M81 with Atik 16ic & CLS through MN56 - Taken in various 3,4 & 5 min subs..

Processing was minimal - Quick stack (no darks) - curves & levels & then a very mild noise reduction. Took 5 mins (amazing how much easier it is to process data when it's good)... Pretty pleased with outcome... :-)

Wed night started clear but time I had setup fog/ clouds had descended so no joy :-(

Anyway hope you like,

John.


(http://homepage.ntlworld.com/john.punnett/graphics/oas/m81.jpg)
Title: Re: M81 - I'm pleased with this....
Post by: Daniel on Feb 15, 2008, 12:14:11
Wow, really nice, I definetly want to try another M81 when i get the chance (added to my already huge list of "must see" objects) really like the definition you've got in the dust lanes there.

Just have to wait for a clear night again now!
Title: Re: M81 - I'm pleased with this....
Post by: Fay on Feb 15, 2008, 12:17:03
John,

I love the detail in the dust lanes, it really is a beautiful image. No darks, that sounds nice.

This can sit beside your M45 & M31.
Title: Re: M81 - I'm pleased with this....
Post by: Carole on Feb 15, 2008, 13:15:24
Excellent.
Looks as good as any published in Astronomy books.

Carole
Title: Re: M81 - I'm pleased with this....
Post by: Ian on Feb 15, 2008, 13:33:52
John, seeing as you're your hardest critic, there's not much more to say if you're pleased with it :)
Are you going to get some colour into it?
Title: Re: M81 - I'm pleased with this....
Post by: JohnP on Feb 15, 2008, 15:01:46
Thks Daniel, Fay, Carole & Ian for comments. Fay the dark current/ noise on my camera is really low & it has virtually no hot or dead pixels so I'm finding I can get away with not taking darks (I should probably still take them but you know what it's like when you are cold & it's late it's the last thing you want to do !)

Ian - I shall probably try & add some colour data but may save it for Tuesnoad at the end of the month... The biggest problem will be lining up /orientating it correctly.


Thanks again,  John
Title: Re: M81 - I'm pleased with this....
Post by: MarkS on Feb 15, 2008, 17:16:09

Nice one John!
Title: Re: M81 - I'm pleased with this....
Post by: JohnP on Feb 16, 2008, 07:58:50
Thks Mark - Appreciate it - John
Title: Re: M81 - I'm pleased with this....
Post by: Tony G on Feb 16, 2008, 12:27:39
Great shot John,

Your Messier chart must be nearly full now (sorry haven't checked it lately) so your'll have to start an NGC chart ;)

Keep up the good work.

Tony G
Title: Re: M81 - I'm pleased with this....
Post by: Whitters on Feb 17, 2008, 04:42:50
Lovely image John
Title: Re: M81 - I'm pleased with this....
Post by: JohnP on Feb 17, 2008, 11:06:29
Thks Tony, Paul.

Tony - I still have a long way to go - I haven't updated my webpage in over a year... :-( The problem is that when you get a new camera or scope you want to go back & redo all the objects again because you are sure you can them better... I'd say it's never ending....

John
Title: Re: M81 - I'm pleased with this....
Post by: Fay on Feb 17, 2008, 12:27:38
John,

I was thinking exactly the same. I look at your M81, my B33, M31 etc etc & think, I am not happy & will have to do them again. You forget the hours spent getting these images that you were satisfied with at the time. Never ending, as you say.
Title: Re: M81 - I'm pleased with this....
Post by: RobertM on Feb 17, 2008, 12:45:29
That's a wonderful picture John, you don't see many out there that good.  I especially like the way you've brought out the detail in the dust lanes near the core.  Can't wait to see a colour version if you get around to doing that.

Robert
Title: Re: M81 - I'm pleased with this....
Post by: JohnP on Feb 17, 2008, 16:23:59
Thks Robert - so far as processing goes it's probably my least processed image - only took 5mins. I think having good data to start with makes it so much easier. all I did was:

- Stacked images in AIP4Win
- Applied a Brightness scaling using Sigmoid transfer function in AIP4Win (this is a bit like doing multiple curves & levels adjustments in PS but you just press a single button) - It's a very powerful image adjustment routine.
- Exported to PS & did crop & final curves/ levels adjustments
- Applied one application of Deep Space Noise reduction in PS Tools..

That was it - 5mins start to finish....

John