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The emission nebula NGC 6334, also known as the Cat's Paw nebula.   It lies about 5,500 light-years away in the constellation Scorpius.

This image is a H-alpha RGB composite.


Image info

Telescope:  Orion 80ED apochromatic refractor at f/7.5

Focus:  Prime focus

Filter:  Astronomik Hydrogen Alpha 13nm FWHM, Astronomik RGB.

Mount:  Vixen GPD with Skysensor2000

Camera:  Artemis 285 CCD camera

Guiding:  700mm refractor guidescope, SAC7 camera, autoguided with Guidedog software

Exposure:  Total 130 mins (26 x 300s) H-alpha, 72, 39, 9 mins R,G,B.

Date:  24th June & 1st July 2006

Processing:  For all frames, offset and flat fielding, registering and stacking done in IRIS.  No dark frames.  RGB combination is first done in IRIS, and star colours are calibrated with a G2V star.  LRGB compositing, curve stretching,  Levels, Smart Sharpen in Photoshop CS2. 

LRGB compositing is through the process of "Luminance Corrected LRGB" as described by Steve Cannistra.  The R component of the RGB is first mixed with H-alpha in Photoshop and then recombined into a new RGB.  The Luminance layer starts as pure H-alpha but with a correction layer whose opacity is reduced in subsequent iterations.  Pls see the link above for details.  Noise reduction in Neat Image.

The stars in the luminance layer were slightly trailed (therefore slightly oval), so this was corrected in Photoshop.




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