Eastern Veil Bi-Color

[Ken Pendlebury]

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

[kwalker]

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.

[Nocturnal]

Great work Ken!

[Silvercup]

Very good result in your first narrow band image.

Hope to see more.

Silvercup

[GB_10D]

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

[Ken Pendlebury]

Thanks Gerhard.  I will give that a shot.  Do you have any examples to show with this method?