Author Topic: Eastern Veil Bi-Color  (Read 5254 times)

Offline Ken Pendlebury

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Eastern Veil Bi-Color
« on: 2011 August 07 16:54:48 »
Hi folks,

This is my attempt at a bi-color (Ha & OIII) version of the eastern veil.  Equipment and exposure details can be found by following the link below.

Here is a summary of the processing approach:
  • Stretch Ha and OIII separately to ensure equal contribution to total signal strength
  • Map Ha to Red and OIII to Blue
  • Create false green channel using Pixel math.  Lots of experimentation here, final was (0.45*Ha + 0.55*OIII)
  • Use hue adjustment to fine-tune colors to liking
  • Neutralize background to remove excessive reds (mask over nebula)
  • Perform HDR Wavelets to enhance tendrils
  • Erode stars to minimize noise (Morph module w/ 7 iterations)
  • ACDNR to cleanup some noise

Please let me know if you have suggestions for improvement.  I'm here to learn and this is my first narrowband attempt.

Full Size:
http://www.flickr.com/photos/kenastro/6020045468/sizes/o/in/photostream/

Exposure Details:
http://www.flickr.com/photos/kenastro/6020045468/in/photostream

Thanks for looking,
Ken
« Last Edit: 2011 August 15 18:37:00 by Ken Pendlebury »
Regards,
Ken
My Astro Photo Stream
http://www.flickr.com/photos/kenastro/

Offline kwalker

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Re: Eastern Veil Bi-Color
« Reply #1 on: 2011 August 07 17:01:04 »
Absolutely gorgeous.
I'm  a DSLR guy and un modified at that so no advice from this end but very curious about ccd for the future.
again a stunning capture.

Offline Nocturnal

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Re: Eastern Veil Bi-Color
« Reply #2 on: 2011 August 07 17:07:30 »
Great work Ken!
Best,

    Sander
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Offline Silvercup

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Re: Eastern Veil Bi-Color
« Reply #3 on: 2011 August 08 16:25:15 »
Very good result in your first narrow band image.

Hope to see more.

Silvercup

Offline GB_10D

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Re: Eastern Veil Bi-Color
« Reply #4 on: 2011 August 09 05:43:24 »
Hi Ken,

A very nice capture of this object, but I would propose a different approach to get the 'true' colors of Ha-OIII emission nebulae, based on their physical properties.
Hydrogen has two strong emission lines in the visible spectrum, Ha(red) and Hb(blue).
OIII(green/blue) is located at the transition of green to blue.

I therefore map the channels like this:
R = Ha
G = OIII
B = OIII+0.15*Ha

This gives a very natural color rendition of emission nebulae.

Best regards,
Gerhard

Offline Ken Pendlebury

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Re: Eastern Veil Bi-Color
« Reply #5 on: 2011 August 15 18:39:56 »
Thanks Gerhard.  I will give that a shot.  Do you have any examples to show with this method?
Regards,
Ken
My Astro Photo Stream
http://www.flickr.com/photos/kenastro/