RCC Request for Feedback and Honest Critique on my Crescent Nebula (Pixinsight User)

Pleiades Astrophoto PixInsight Processing One-Shot Color Request for feedback
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Tommy Mastro avatar
Tommy Mastro avatar

Hi there. I spent three hours processing this and I am not thrilled at all. It seems the longer I take to process an image, the worse it comes out. Any critique would be appreciated.

My Pixinsight workflow is:

  • Crop and Image Solve

  • ABE or Gradient Correction (in this case Gradient Correction was used).

  • SPCC

  • BXT, then NXT, then StarXT

  • Seti Astro Statistical Stretch for Starless and Seti Star Stretch for Stars

  • Curves Transformation for contrast and saturation and Saturation Curves for targeted saturation.

  • Local Histogram EQ

  • Dark Structures Enhance

  • MultiLinear Transformation for clarity

  • Add artificial Spikes to stars

  • Screen Stars Back in

  • Final tweak in Curves

📷 Crescent_WF_Final_16_TW_JPEG.jpegCrescent_WF_Final_16_TW_JPEG.jpeg

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Tony Gondola avatar
Tony Gondola avatar

Love the composition and I think your color choices are good. What is it that you see that needs improvement?

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andrea tasselli avatar
andrea tasselli avatar
To start I'd never add spikes to stars as they look absolutely fake. Your OIII is too blue as well and the stars too clipped. You also have blue halos around a lot of them, not sure where these come from. The stretching is flattening the imaging way too much and you want more in intensity gradient rather then less. Also, it is way over-smoothed, again lending to an artificial "plasticky" look. You don't really need BXT at that image scale so don't (or just to correct obvious aberrations). I would use only 2 steps in stretching and neither of the have anything to do with this SETI thing. Less is more, all the time.
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Tommy Mastro avatar
Tommy Mastro avatar

Hi Tony,

I feel like its too 2-Dimensional. It doesn’t have that 3D feel so many images like this have.

And those medium sized stars around the Crescent Nebula have pretty bad haloes. I tried using the Halo control in BlurX but it didn’t help much.

Tommy Mastro avatar
Tommy Mastro avatar

andrea tasselli · Mar 8, 2026, 08:49 PM

This is all great info. If you don’t mind, could you please expand on the following.

the stars too clipped. (what do you mean by this? Keep in mind, I’m still a noob to some extent)

The stretching is flattening the imaging way too much (does this mean I over-stretched? Or under stretched?)

you want more in intensity gradient rather then less. (I’m not sure what this means either. Does this mean I shouldn’t use Gradient correction? )

Thanks@!

Tommy

andrea tasselli avatar
andrea tasselli avatar
Hi Tommy,

I think the best way in these cases is to let others have a go and learn how they achieved their results if you like them.

To answer your points:

Stars, or rather their PSF have wings since they can be though as having a gaussian distribution of light from a peak to the background level (of sorts but I digress). In your case they look like point of circle of light with no tapering of brightness from center to edge (and with little colour to boot). If you use BXT slide the top slider all the way to the left to avoid compressing the PSF to tiny pin-pricks of light with no "wings". 

I don't know how you stretched the image as I don't use the tools you used but its effect is to flatten the highlight and dim the shadows whilst you want to compress the dynamic range in order to show the shadows and the mid-tones as well avoiding too much flattening of the highlights. So in a way it is under stretched and the mid-tones flattened (not enough dynamic range) against the highlights.

And, no, I wouldn't use Gradient Correction at all. Any further adjustment besides the basic stretching is to be achieved through the use of Curves, normally in the lower half of the range. And no saturation fiddling, that's the job of the stretching.
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Tommy Mastro avatar
Tommy Mastro avatar

andrea tasselli · Mar 8, 2026, 10:29 PM

Hi Tommy,

I think the best way in these cases is to let others have a go and learn how they achieved their results if you like them.

To answer your points:

Stars, or rather their PSF have wings since they can be though as having a gaussian distribution of light from a peak to the background level (of sorts but I digress). In your case they look like point of circle of light with no tapering of brightness from center to edge (and with little colour to boot). If you use BXT slide the top slider all the way to the left to avoid compressing the PSF to tiny pin-pricks of light with no "wings". 

I don't know how you stretched the image as I don't use the tools you used but its effect is to flatten the highlight and dim the shadows whilst you want to compress the dynamic range in order to show the shadows and the mid-tones as well avoiding too much flattening of the highlights. So in a way it is under stretched and the mid-tones flattened (not enough dynamic range) against the highlights.

Wow, the tool I used to stretch actually has a slider for compressing Dynamic Range. I guess I need to figure out how to use it or use a different stretching tool.

Regarding BlurX, you are basically saying to use the “correct Only'“ tool or keep the “sharpen Stars” slider to a very low value. This is interesting because I’ve always noticed (and hated) that my stars only have color on a rim around the outside perimeter of the star while the center of the star has no color at all! What we want is for the stars’ light to taper off into the background, assuming I am understanding correctly.

This could also be from too much contrast I would think. I’ll be sure to only use my contrast curves on a starless image and to take it very easy with BlurX.

Thank you for the help, very much appreciated!

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