[RCC] Excessive stars on image of North American Nebula - Forums

Topic starter

Jul 21, 2023 · Edited: Jul 21, 2023

I'm having difficulty cleaning up background stars (bluish-greenish pixels) in this image taken with my ASI2600MC Pro with an Optolong L-enhance filter. Image processed with PII using WBPP with flats and bias frames, stretched, denoised and both background extracted and neutralized.

I've extracted a star mask with StarXTerminator and tried SCNR on it with different settings, but to no avail. I also tried BillsStarReductionMethods. Again, the stars were not reduced.

Any suggestions on how best to process the image would be appreciated.

North American Nebula

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Joe Linington

Jul 21, 2023

A few questions, did you extract the stars before or after stretching? Do you have affinity? Do you have BlurXterminator?

wsg

Jul 21, 2023 · Edited: Jul 21, 2023

I just ran a screen steal of your image through SCNR and it worked fine.

Used the default setting, pressed the button.

Glenn Silverman

Topic starter

Jul 22, 2023

Joe Linington:
A few questions, did you extract the stars before or after stretching? Do you have affinity? Do you have BlurXterminator?

I ran StarXTerminator on a stretched image and that worked fine. It left me with a star mask and a starless nebula. I don't have BlurXterminator. Would that do that trick?

Glenn

Glenn Silverman

Topic starter

Jul 22, 2023

Also, in reply to the message about SCNR, I wasn't able to discern much difference with the before and after. I tried with all 3 colors, green, red and blue.

Glenn

Dave Rust

Jul 22, 2023

This looks about right. There are more stars than even this image shows! Good job.

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KIJJA JEARWATTANAKANOK

Jul 22, 2023 · Edited: Jul 28, 2023

Hi Glenn,

I think the 'just right' stars is also relative to the nebula's brightness and saturation . I downloaded your image and applied the following processes : color calibration, (but couldn’t perform SPCC because plate solve failed) separate stars, and increased saturation to the starless image, stars reduction using morphological transformation to the stars image and re-combined the stars back via pixel math. Here is my interpretation of your image.

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Joe Linington

Jul 22, 2023

Glenn Silverman:
Joe Linington:
A few questions, did you extract the stars before or after stretching? Do you have affinity? Do you have BlurXterminator?

I ran StarXTerminator on a stretched image and that worked fine. It left me with a star mask and a starless nebula. I don't have BlurXterminator. Would that do that trick?

Glenn

I always remove the stars before stretching, this lets you stretch them separately an control how many come out much better, you can also control the halo's better too. I asked about the other tools, not because any particular one is a killer but so I could suggest some processes. With what you have, you could split the stars into their RGB components and then use the EZ decon or EZ star reduction on the problem channel. The EZ suite is free and makes Decon a little simpler. Carefully applied and then recombined and stretched it can solve some pretty hefty halo issues. I use BXT on my blue channel when doing RGB stars with my doublet to reduce the nasty blue haloes and then anything left I clean up in Affinity using the JR Remove Halo macro.

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Scott Horton

Oct 30, 2023

Hi Glenn,
I also image with the 2600MC pro and LEnhance. I think I can help!
My process:
Linear image –> DBE –> SPCC (be sure to put in your sensor and choose the L Enhance filter options) –> SXT.
Then stretch your stars and apply SCNR. I always stretch my stars separate to control brightness, bloat, how many you want to show etc.
Process your starless image as you please then recombine in Pixel Math.

Bills star reduction PM is excellent but fussy - as the formula is written you must make sure your images are named Starless and Stars, you should drop the PM formula to recombine the two onto your Stars image then use the reduction PM on your stars image. If you add the stars to your nebula then use the reduction script on the starless image it wont work as written.

He has also updated the PM to an actual process now with a preview.

Hope this helps and feel free to reach out if you need clarification.

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