Seeing (too many) stars

[+Stu]

Hi folks. So my IC417 image, and the recent heart nebula one have a lot of stars. I'm not totally against it as it looks pretty cool, but........ Is there a method of reducing the amount in the final image? To make it look a bit neater. I've tried a star reduction process in Affinity but it can leave little black rings when trying to use it on such a packed image. Would simply doing shorter subs but more of them be effective?

[+Ibbo]

Thats one way.

 

Can you use Star Net to extract the stars and process them separately?

Thats how I do it in PI

[+Stu]

@Ibbo I've used StarXTerminator before but not really done much with the stars layer before merging them with the background. Is there a particular way to do it? It'd be good to remove all the faint ones to make it look less cluttered but still have plenty of brighter ones left. 

[+Stu]

@IbboI had a go with StarXTerminator in Affinity. It's a better result than when i've tried it before.

 

[+Ibbo]

Using PI I

1 Crop

2 Gradient removal

3 SPCC for colour calibration

4 Blur X to correct stars

5 Remove stars

6 Blur X to deconvolve

7Noise X

8Stretch Background & stars separately

9 Curves for saturation and contrast

10 Combine satrs and background

11 fiddle around with masks for selective sharpening (if it works)

 

Edited March 16 by Ibbo

[+Stu]

@Ibbo Masks is something I need to find a tutorial on for Affinity. I think Blur X is only available for PI. I might get it one day but I need a lot more clear skies to justify the price.

[+Ibbo]

I struggle with masks as well.

 

If you want drop your image in Dropbox as a fits or tiff after you do your crop and gradient anfd I will Blur X for you.

[Clive]

I've been playing about with a star removal/replacement tool for a few years now (since I retired). It is still very much work in progress as I continually tweak it but I've had a 'working' version for a couple of years that can selectively remove stars.  Removing the fainter stars is easy, it's the bright ones that are more difficult to remove without leaving residual artifacts.  Unfortunately I haven't yet got around to making a stand alone version that can take any image file type...it currently only works under MS Excel with IRIS format image files. If you do post the image on Dropbox I can convert it to the IRIS format, try to remove the faint stars and then save the result in the original image format. (Note that the image must still be linear, i.e. unlike StarNet, the image should not be stretched prior to star removal)

[+Stu]

@Ibbo @Clive Thank you both. I'm still chasing an image with a "proper" amount of integration time but when I do I may take you up on the offers. 

In the above image I separated the stars with Star X, played with brightness/contrast on the background and reduced the gamma on the stars layer. Still lots to learn, this rabbit hole sure is deep 😄

[Bottletopburly]

@Stu give Siril star reduction script a bash , details in the video 

 

[+Stu]

@Bottletopburly Cheers, I'll give that a go. I've been watching a few guides by James Ritson for Affinity and he's produced a load of astrophotography macros to add on, they look like they could be quite useful.