Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: RobertM on Apr 29, 2009, 21:55:39

Title: B355 - Part of NGC7000 the North America Nebula
Post by: RobertM on Apr 29, 2009, 21:55:39
Have processed this to try and bring out the dark dust lanes so this version is a bit over stretched.  Could also have done with some more subs but dawn beckoned.

4 x 1200s Ha sub exposures from Kelling combined in MaximDL and processed in PS.
Sky90@f4.5 SXV-H9 and Astronomik 13nm Ha filter.

Thanks
Robert

(http://farm4.static.flickr.com/3603/3487170940_15ffc5b6b5_o.jpg)
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: Ian on Apr 29, 2009, 23:02:17
blimey, nice image. Part of a mosaic maybe?
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: MarkS on Apr 30, 2009, 06:23:12

Excellent image Robert.  You have lots of detail in there and good sharp stars. 

I can't believe you did 20 minute exposures without trailing out in a field!  How did you perform your polar alignment?

Mark
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: RobertM on Apr 30, 2009, 08:26:57
Ian, NGC7000 is very large so I'm not sure about a mosaic as it would take a few weeks even with clear skies.  Would make a good project for DSC, combined with a couple of DSLR shots for colour...now there's a thought !

Stars in the bottom right are still a little out of focus but hopefully after regreasing and adjusting the focuser (found a key set screw) last night it will be better next time.

Mark, Polar alignment is via the polar scope.  In fact I was doing some tests last night with PoleAlignMax and the Polar scope gets me to within 1 arc min as well as being much quicker.  Unfortunately the Cherry tree in the next garden is starting to obscure Polaris so I have to start doing it a different way soon (hence the trial of PAM).

Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: Fay on Apr 30, 2009, 08:31:53
Very nice Robert, Cygnus is coming around again, all those lovely nebulae!
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: RobertM on Apr 30, 2009, 17:52:04
Didn't like that image (followed someone elses processing advice) so I've deleted it and done it the way I normally do.  I hope you think it's better and more natural looking!

(http://farm4.static.flickr.com/3618/3488456297_9cd48a7e58_o.jpg)
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: Ian on Apr 30, 2009, 17:55:18
I'd say that one's a mite oversharpened, but I can't compare it to the previous one, you've deleted it...
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: RobertM on Apr 30, 2009, 18:02:28
You're right it does and I didn't need to do it so much ... Mk3 is on the horizon ...
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: Daniel on May 01, 2009, 00:39:23
Nice image Robert, although I agree, it's a tad oversharpened. Do you use drizzle with your stacking, or is this the resolution your camera gives you, looks great, I've just sorted out my tax woes, so my mind is turning to astro camera's again!

Daniel
:O)
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: RobertM on May 01, 2009, 07:42:46
Hi Daniel, That is native resolution, no drizzle or any other resampling was used.  It is undersampled though at about 3.4 arcsec/pixel but there isn't much I can do about that apart from drizzle and there weren't enough subs for that.

A new camera - that's going to be a tricky choice unless your pockets are very deep !
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: Daniel on May 01, 2009, 19:57:02
If only there was a chip the size of the MX25C in Mono, that would be perfect for me, anything bigger than that, vignettes a bit too much on the Hyperstar.

Daniel
:O)
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: RobertM on May 01, 2009, 20:26:52
What you mean like the QHY9 or QSI 8300, FLI-8300 etc ?
Title: Re: B355 - Part of NGC7000 the North America Nebula
Post by: Daniel on May 02, 2009, 14:07:43
Oh, errrrrm, yes those would be good!  :oops:

Hmmm, the QHY is looking good (and cheaper than the rest)

Daniel
:O)