Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: JohnP on Dec 31, 2009, 16:16:12

Title: Tadpole...
Post by: JohnP on Dec 31, 2009, 16:16:12
Taken night of 20th Dec - using Atik 16ic + Ha 13nm + ZS66. Snow on ground & moon around (at least at start).. 20 X 5mins. My first image in 3 1/2 months - good to get all the equip working again. Needs a lot more subs to reduce noise & colour to be added..

Taken - Central Bromley.

Cheers,  John

(http://jpastronomy.co.uk/graphics/oas/tadpole_1.jpg)

Title: Re: Tadpole...
Post by: Daniel on Dec 31, 2009, 16:46:31
That's a lovely image John, and how you got in so close to the tadpoles themselves with that level of detail with the ZS66 is fantastic. I never get enough detail imaging the tadpoles myself with the hyperstar and that would probably have wroughly the same FOV.

Excellent work

Daniel
:O)
Title: Re: Tadpole...
Post by: Fay on Dec 31, 2009, 16:58:59
That has come up really well, John. Glad you have been outside & enjoyed it! I can't get into the swing of lining it up when subs are takren on a different night.
How do you do it?
Title: Re: Tadpole...
Post by: JohnP on Dec 31, 2009, 17:16:15
Daniel remember Atik 16ic has a small chip - only 3.7 X 4.9mm (640X480) so effective FOV with ZS66 is 32 X 43 arcmin - The imaging scale is approx 4 arcsec/pixel...

I enlarged image to 1000 pixels wide (from 640) using pshop for display...



Fay - Thks for your comments. On the same night I did the Tadpole I actally took some RGB subs for an m33 L image I took at Les Granges over a year ago. The technique I use for alignment is open one of the old subs from a year ago in Aip4win or any image processing software - you can then run the cursor over the image & get the X & Y coords of a prominate star or two... Then take short subs of the image you want to image & compare positions. If you are using the same imaging equipment etc. it's normally then just a case of rotating camera until two stars line up.... As long as you get within 10 pixels or so your alignment software should happily take care of anything else when you stack...


John
Title: Re: Tadpole...
Post by: RobertM on Dec 31, 2009, 18:35:01
Wonderful image John and excellent resolution.  I know you haven't had much time so it's really great to see you're getting out there again.

Robert
Title: Re: Tadpole...
Post by: Fay on Dec 31, 2009, 18:45:38
That is what I try to do John & it takes me ages to get it lined up....will have to try harder!
Title: Re: Tadpole...
Post by: Carole on Dec 31, 2009, 19:07:57
Really nice John.  Looking forward to the colour version.

Carole
Title: Re: Tadpole...
Post by: Tony G on Dec 31, 2009, 20:15:48
Good to see you imaging again, and everything working OK. Its good when that happens. ;)

Keep them coming.  :)

Tony G
Title: Re: Tadpole...
Post by: JohnP on Jan 01, 2010, 11:26:41
Thks Robert, Fay, Carole & Tony for your comments - much appreciated. John
Title: Re: Tadpole...
Post by: MarkS on Jan 03, 2010, 15:03:06

Lovely image John and nicely processed with excellent contrast. 

Good to see you imaging again!

Mark
Title: Re: Tadpole...
Post by: JohnP on Jan 03, 2010, 17:12:19
Thks Mark - There is a lot of room for improvement but as its first image in nearly 4 mths I was happy everything worked....

John