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Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: MarkS on Mar 18, 2009, 06:33:58

Title: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: MarkS on Mar 18, 2009, 06:33:58
First light with my newly acquired Skywatcher ED80 (thanks Robert!) using the Canon EOS 350D at F7.5  - I shot this data just a few hours before leaving on holiday.

150 images of 30sec shot during a 90 minute period. Sigma stacked on the comet head to enhance comet against star background.  No filters were used, which meant that removing the background gradient was a nightmare.  The tail still gets lost in a gradient at the bottom left.  This is almost the whole frame but binned down by a factor of 5 to reduce noise.

Mark

(http://gallery.orpington-astronomy.org.uk/albums/userpics/10046/lulin280209.jpg)
Title: Re: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: RobertM on Mar 18, 2009, 08:05:04
Very nice Mark, the comet is quite faint now so that's a very good capture.
Title: Re: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: Rocket Pooch on Mar 18, 2009, 08:55:54
Very good, how are you finding the ED80?  Do you get any field curvature on the frame.
Title: Re: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: MarkS on Mar 18, 2009, 09:29:52
Quote from: Space Dog
Very good, how are you finding the ED80?  Do you get any field curvature on the frame.

Yes, there is noticeable field curvature when using the Canon with it.  I'm going to try some experiments with my existing Celestron Reducer/Flattener to see if I can flatten the field by finding an optimum flattener to CCD distance.  I have just taken delivery of a set of spacing rings.

Mark
Title: Re: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: Fay on Mar 18, 2009, 10:53:40
Well done, Mark, as usual you always get your man!
Title: Re: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: JohnP on Mar 18, 2009, 11:15:00
QuoteWell done, Mark, as usual you always get your man!

Fay - what do you mean......!!!!!

Great image by the way Mark.

John
Title: Re: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: Mike on Mar 18, 2009, 11:21:49
Nice image Mark. You did well to get it so late into March.
Title: Re: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: MarkS on Mar 18, 2009, 11:25:28

Thanks for the comments.  Just to clarify, I shot the data at the end of Feb - not last night!

Hence the title of the thread:  "Re: Comet C/2007 N3 Lulin on Sat 28 Feb"

Mark
Title: Re: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: Fay on Mar 18, 2009, 12:53:34
John, what I mean is, Mark is always successful in  what he does!!!
Title: Re: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: Ian on Mar 18, 2009, 13:00:35
particularly if he's got his eye on a particular man? Is that right Fay?

Congrats on the image Mark, nice one mate. Does this mean you're not going to be lugging the C11 to DSC anymore?
Title: Re: Comet C/2007 N3 Lulin on Sat 28 Feb
Post by: MarkS on Mar 18, 2009, 21:08:32
Quote from: Ian
Does this mean you're not going to be lugging the C11 to DSC anymore?

Not at all!   It's horses for courses.  The C11 is a terrific scope for close-up high magnification work.  But from time to time it's good to do some wide-field stuff.  Hence the ED80.

Mark
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