Improving my glob cluster results

[ballyhoo]

I hope this is not asking a lot from members here, but I would really like to know if there is potential for post processing improvement on this image?
What appears to me is that I would like to extract luminance from the core, but I was not successful in this case. Re process LRGB comb, I have the  sat slider at .2 and lightness slider at .5, nonetheless I had tried several combinations and this was what I came up with.

https://www.astrobin.com/417620/

fit file:

https://www.dropbox.com/s/0rhwxh9irgaaqum/M15.fit?dl=0

Thank you so much!

[ngc1535]

Hi Ballyhoo,

Some things:
1. You provided a permanently stretched color image that is a FIT file.  I would have expected it a combined file that is a linear image in the XISF format.
2. Since the image is permanently stretched, your decisions are..well permanent. I think the perhaps the linear RGB (or L and RGB)  would be more useful to see different "improvements" you might consider. For example, if you want to have the core show more stars...perhaps HDRMT would be helpful.
3. You mentioned extracting the luminance from this color image- but for what purpose? (What did you want to do next?) Once the information is clipped in either the Lumiance or the RGB images- there isn't much you can do to recover (detail or color). The adjustment needs to be a little earlier.
Is this the kind of information you were looking for?

-adam

[ballyhoo]

Hello, my decisions are not permanent because I can just  re-integrate the image and process once again. But how should I approach the process differently?

This was done OSC, would I still do the linear RGB? I am not sure of all the terminology.

[pfile]

what adam is saying is the fits file you posted is useless, because your processing is baked into it permanently. no one can process it any differently, or offer you any advice, because the image is already stretched.

if you want processing advice you have to post linear images.

rob

[John_Gill]

Hi,

Hi,

There are a couple of issues with your image...

The big stars are bloated and over saturated and have a red fringe around them.
The core of the globular cluster is over saturated and lacks any detail and the stars have turned yellow with red in the background.
I think you should reprocess the image with a very much lighter touch.... perhaps process very lightly and then process again with in-between settings...

I looked at your various revisions on "Astrobin" and the original image (which still has some problems) is far better than the resultant image.

Hope this helps
John

[Andres.Pozo]

what adam is saying is the fits file you posted is useless, because your processing is baked into it permanently. no one can process it any differently, or offer you any advice, because the image is already stretched.

if you want processing advice you have to post linear images.

rob

To further clarify Rob's suggestion, you should post the image that results from the integration step, before any color calibration, background subtraction, convolutions and, especially, before any histogram operation.

Andrés.