Omega Centauri

[Paulyman]

Hi all,



I thought I'd share an image of Omega Centauri I took the other night. We have finally had a good run of clear nights, the first in six months so I was out imaging from dusk until dawn, the astronomical equivalents anyway. This is 3 hours of RGB data, I also captured 2 hours of luminance but combining LRGB is a step beyond me at the moment, at least in terms of getting the balance right.



60x60sx3 RGB

ZWO 183MM-Pro

WO Star 71

CEM40

Processed in PixInsight



I actually learned a new technique thanks to the Adam Block tutorials. Using ArcSinh Stretch and Masked Stretch to control the stars and maintain good colour took its toll on the brightest stars, particularly the big blue/white one just to the top left of the cluster. It could also have been deconvolution, either way the process left an absolutely horrid inner bright blue ring in the core. Thanks to one Adam's tutorials I was able to mask it using the GAME script and add back a more appropriately stretched version of it from the original RGB image. I didn't manage a perfect copy of Adam's technique but at least at 1-1 it looks passable.

Link to the higher res image below:


https://astrob.in/d2eo9r/0/

[Saturnine]

:thumbsup::thumbsup::thumbsup:

[Placidus]

Excellent. Nice feeling for the strong ellipticity, the full extent of the cluster, and the colour.

[Geoff45]

Good detail right down to the core. Nicely done Paul.
Regarding comments about LRGB vs GRB: I have always found that plain RGB usually works well for star clusters--open or globular.


Your second point about using arcsinh stretch is a good one. It works very well with star clusters, but I find not so well with galaxies.

[Paulyman]

Thanks guys. I am slowly learning not to push my data too hard and let it speak for itself, I think this is the first time I've actually succeeded.