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View Full Version here: : Pelican nebula 1st attempt at colour emission line imaging


Paramount
06-06-2008, 09:36 PM
Hi all
After an abysmal May as far as weather is concerned I have finally got my filter wheel up and running and as the sky was clear last night (it was up till mn) I thought I'd chance my luck and have a go at the Pelican nebula. After I got everything aligned I was ready to begin just before 12mn but as the camera was taking its dark frame for auto dark subtraction patchy clouds started rolling in from the southwest and this was the pattern for much of the rest of the evening. I decided to stick with it though and managed to shoot 7x10 minute unguided each of Ha, OIII and SII (the last one of the OIII and SII had to be junked because daylight stopped play). The was a period of about an hour when there was no cloud at all but the rest of the time patchy clooud came very close to cygnus and on a few occasions covered where I was imaging (thankfully only for a few seconds each time)
I combined the 6x10 minute SII(red), 7x10 minute Ha (green) and 6x10 minute OIII (blue) Hubble palette style. Onle 3 small iterations of curves were used as well local area contrast in Noels tools. No levels were used. Considering the rush and the threatening cloud I am well chuffed. I have also enclosed a cropped close up of the Pelicans "neck" to show the chimneys a bit better.
Thanks for looking
Clear skies
Gordon
:)

http://www.imagingtheheavens.co.uk/USERIMAGES/Pelican-nebula-hubble-palle.jpg

http://www.imagingtheheavens.co.uk/USERIMAGES/Pelican-closeup.jpg

leon
06-06-2008, 09:57 PM
Gordon that is a fine image, I can't recall ever hearing of this object, however you have captured it very well indeed.

Leon

jase
06-06-2008, 10:01 PM
Great work Gordon. Pleasing to see some colour images from you at last, be in mapped compared to conventional RGB. You've obviously got your imaging train woes resolved. The balance between the emissions lines looks aesthetic, though for the quantity of data you've got, it does appear rather noisy and processing looks black clipped. I would have expected a better result. Perhaps there is more data hiding there. Don't be afraid to go 20min or 30min subs with narrowband filters. You've got a mount that will handle it at least. Geez, with the short FL of the TMB115 and protrack it'll probably go 45min unguided and still deliver round stars.

To put you on the one of the many paths in narrowband processing, I recommend you watch the video "The Basics of Clipping Masks (http://rdelsol.com/Presentations.html)" by Ken Crawford. Clipping Masks provides incredible flexibility in balancing the emission lines. Of course, there are other ways you can handle the task. Look forward to seeing more.

Alchemy
06-06-2008, 10:25 PM
well it is different. be interesting to see how you progress with this sort of imaging.

vash
06-06-2008, 11:05 PM
Nice image,
That is the first image that I have ever seen that I can clearly see the pelican in it