How to get better background extraction in editing!

I’m a post-processing minimalist. So I use Light Pollution filters as a rule with my AP rig.

Quell the light pollution before it enters my camera. It works best for me and my desired results.

I just do a quick check for images that are obviously bad, mostly at the end of a night’s images and delete the bad ones. Then stack the rest and let the stacking sort out the ones with Airplanes or Satellite’s and save my results for web presentation.

I’ve always been a proponent of using astro-cameras because they are mostly cooled sensors to eliminate noise. (I do have an Atik Infinity OSC that isn’t cooled that took great images). To me, cooled Astro-Cameras are just the right tool for the job. My DSLR is great for terrestrial shots, Grandkids soccer, Hummingbirds. But for astronomy I like my Astro Cameras.

I’d suggest you try using a filter, rather than trying to fix a bad image. My current AP camera has an APS-C color sensor and works dandy with 2” LP filters.

SonnyE · Mar 17, 2026, 07:13 PM

I’m a post-processing minimalist. So I use Light Pollution filters as a rule with my AP rig.

Quell the light pollution before it enters my camera. It works best for me and my desired results.

I just do a quick check for images that are obviously bad, mostly at the end of a night’s images and delete the bad ones. Then stack the rest and let the stacking sort out the ones with Airplanes or Satellite’s and save my results for web presentation.

I’ve always been a proponent of using astro-cameras because they are mostly cooled sensors to eliminate noise. (I do have an Atik Infinity OSC that isn’t cooled that took great images). To me, cooled Astro-Cameras are just the right tool for the job. My DSLR is great for terrestrial shots, Grandkids soccer, Hummingbirds. But for astronomy I like my Astro Cameras.

I’d suggest you try using a filter, rather than trying to fix a bad image. My current AP camera has an APS-C color sensor and works dandy with 2” LP filters.

Thank you so much for the feedback! I just ordered a svbony CLS LP Filter. I should be receiving it tomorrow, Ill probably post results on my profile once I get it if you ever want to see how they turn out!

Horriblebaby · Mar 17, 2026, 10:39 PM

Tony Gondola · Mar 17, 2026, 07:56 PM

It looks like you did a good job of getting rid of the gradient. On the background, you can control the black point a lot of ways in Siril. I’d recommend learning how to use the histogram tool and the curves tool.

I will try and give learning the curves/histogram tool a shot! Thank you so much for all your help, I’m really new to this hobby and knowing I have people that can help me when I’m confused or don’t know what to do really helps :)!

Hey, it’s a long road and even those of us who have been at this for awhile still need to lean on each other for help and advice.

I agree with what has been said, it looks like you have done a good job of removing the gradient across the image, which is really important. You want a flat background, but not an absolutely black one.

Now, with the gradient gone, you can "stretch the image using a variety of tools, and part of this process is setting the black point. You want this to be set so that the background is dark and true noise is decreased, but if you get too aggressive then the background is too dark and it looks weird and artificial. Don’t think of it as extracting the background anymore, but rather as adjusting how the linear data is transformed into an image that is suitable to display.