This nebula has a large brightness range right down to the black dust blob left of centre. The S2 filter seems to give the best definition away from the Swan shape with Ha giving detail to the Swan shape itself with O3 providing the colour. Used MartinPugh's excellent image as a guide but colour came quite easily with this bright object. It is 5-6,000lyrs away similar distance to the Eagle nebula.
This nebula has a large brightness range right down to the black dust blob left of centre. The S2 filter seems to give the best definition away from the Swan shape with Ha giving detail to the Swan shape itself with O3 providing the colour. Used MartinPugh's excellent image as a guide but colour came quite easily with this bright object. It is 5-6,000lyrs away similar distance to the Eagle nebula.
S2-18x10m
Ha-12x5m
O3-12x10m
RGB-10x2m each.
Image1-Hubblepalette.
Image2-S2 RGB for stars.
Images at full resolution.
Thanks, John.
Hate to admit but my choice is for the narrowband..
Very nice results John, impressive resolution
Thanks for comments, I must admit the RGB stars I always seem to have trouble with, they never look natural thats why the HubblePalette image still has its pinkish stars. I did not use a minimum filter on the stars which may have helped and stars are too bold. Perhaps S2 was not good enough to use as a luminance but its all an experiment.
The Ha HaRGB image below seemed to be a little better but still not right.
Regards, John.
Last edited by John Hothersall; 22-09-2011 at 12:27 AM.
That last rgb version is much better, it's the type of detail in the nebulosity that made me ask before, a minimum filter whilst shrinking stars also makes other detail " clump" together, M17 is particularly difficult in that it has wavefronts all through the nebulosity, and using a minimum filter causes a spiderweb like appearance. Some tools such as carboni's make stars smaller incorporate a minimum filter within, and it's applied across the image.
As I said, this version is much better, and it's not just to do with the stars.
Thanks for comments and Clive I can see the pinching, I spent too long looking at this and knew it was off somehow, I used HighPass too liberally but found Minimum filter on the stars helped but S2 was difficult to get right, but I appreciate feedback.
Thanks for comments, I must admit the RGB stars I always seem to have trouble with, they never look natural thats why the HubblePalette image still has its pinkish stars. I did not use a minimum filter on the stars which may have helped and stars are too bold. Perhaps S2 was not good enough to use as a luminance but its all an experiment.
The Ha HaRGB image below seemed to be a little better but still not right.
Regards, John.
You've got to process the stars in a separate layer and replace the NB ones using a layer or layer mask. Often a simple "lighten" mode layer and boost it up with curves a bit to shine through will replace the NB stars.
Otherwise select the stars colour range tool/highlights. Expand the selection a few pixels and feather it half of the expansion.
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