Halos left after fringe killer - Startools

[AstroNebulee]

Hi
I am using star tools 1.8 and after using fringe killer in the filter module im left with a grey halo that i just cannot get rid of in any other module.

Could someone please help me in bringing the halo tighter to the star core.
My workflow to this point is:
Autodev-Bin-Crop-Wipe-Autodev (with roi)-Contrast-HDR-Sharp-SV decon sv mode-Colour-Filter fringe killer.
I have tried lots of combinations in the shrink module but cannot get rid of it.
My setup is skywatcher 72ed az gti in eq mode, zwo 294 mcpro with 2 inch zwo ir uv cut filter, guiding with zwo f4 guidescope using an asiair pro.

I shall add the full unstreched tif file when home from work. I have attached a screenshot of the issue and tif file of the process after using fringe killer. 

I should add I have used the astronomy tool reduce purple halos in photoshop cs4 version 11 and leaves a grey halo around the star making it look awful on nebulae. 

Startools after fringe killer.tiff

Edited March 18, 2022 by AstroNebulee

[happy-kat]

There are some tips in the startools forum under user notes on special techniques, covers CA.

My current preference is to using a mask exclude the CA prone stars from the colour module so they remain in luminance state, though the user notes allows for fine tuning of the blue bloat.

Edited March 18, 2022 by happy-kat

[AstroNebulee]

58 minutes ago, happy-kat said:

There are some tips in the startools forum under user notes on special techniques, covers CA.

My current preference is to using a mask exclude the CA prone stars from the colour module so they remain in luminance state, though the user notes allows for fine tuning of the blue bloat.

Thank you I shall have a look at that. I can see what you mean with this, I have a shed load of stars with the purple fringing, it would be nice if there was a way of really tightening and the halo left behind. I find that the sv decon module tightens up the core and leaves a big halo no matter which decon mode I try. I will look at user notes in the forum. Edit..... now read the special instructions and will try it and see if it helps. 👍

Edited March 18, 2022 by AstroNebulee

[happy-kat]

You should be able to tighten the blue up using the notes method I think as you work just on that channel.

[symmetal]

To remove any halos left after processing with Startools, I use Photoshop rather than the Startools fringe killer, using this handy tip. It uses the camera raw de-fringing option which is selectable as a filter. Not sure if CS4 has all the features mentioned but here's an example using a crop of the Sadr region. Normally you don't need to mask the image beforehand but with Sadr itself it took several passes using the filter so I made a soft-edged masked around Sadr.  Here's a before/after:

Alan

 

[AstroNebulee]

50 minutes ago, symmetal said:

To remove any halos left after processing with Startools, I use Photoshop rather than the Startools fringe killer, using this handy tip. It uses the camera raw de-fringing option which is selectable as a filter. Not sure if CS4 has all the features mentioned but here's an example using a crop of the Sadr region. Normally you don't need to mask the image beforehand but with Sadr itself it took several passes using the filter so I made a soft-edged masked around Sadr.  Here's a before/after:

Alan

 

Thank you, I've tried in my version of photoshop it doesn't seem to do a great job on it to be fair. I'll attach the tiff file of the steps before I'd use the fringe killer in startools.  Im completely at a loss for a moment and will have to step away for a few hours I think.

Before fringe killer.tiff

[AstroNebulee]

1 hour ago, happy-kat said:

You should be able to tighten the blue up using the notes method I think as you work just on that channel.

I have tried this but they still have the grey halo around the star, something im missing here i think.

[happy-kat]

I've found its about managing the CA and making it less obvious, getting rid totally is perhaps less obtainable, stopping down is one option as is just being off focus making CA less strong.

[symmetal]

I've used the latest PS CC camera raw de-fringe on your posted image. Your blue halos have a solid hard edge and are clipped while the red and green halos fade into the background, so  de-fringing blue will leave you with a hard grey edge. On the sample I posted the blue halo fades into the background so the defringe tool can leave the underlying yellow while neutralising the blue, giving a nicer edge.

Alan

 

[AstroNebulee]

8 minutes ago, symmetal said:

I've used the latest PS CC camera raw de-fringe on your posted image. Your blue halos have a solid hard edge and are clipped while the red and green halos fade into the background, so  de-fringing blue will leave you with a hard grey edge. On the sample I posted the blue halo fades into the background so the defringe tool can leave the underlying yellow while neutralising the blue, giving a nicer edge.

Alan

 

That's looks quite lovely indeed. I think I will have to accept some grey halo around the stars in this image. It's giving them a softness too. Sadly my version of photoshop camera raw cannot cope with this. I shall have to find a workaround somehow. Like I said if I could soften the edges of the halo would be good enough I think. Thank you for trying to help this baffoon 👍

[AstroNebulee]

1 hour ago, happy-kat said:

I've found its about managing the CA and making it less obvious, getting rid totally is perhaps less obtainable, stopping down is one option as is just being off focus making CA less strong.

Your correct happy kat, it'll be a case of making the halos less obvious with the CA in processing. Thank you for trying to help me too 👍

[happy-kat]

Another idea would be to process the image and using Heal create a star less image to process the nebula. Then start again and using develop a conservative stretch for the stars mask and save (the pdf manual has how to use Heal module for starless image may need a couple passes), then use the Layer module to combine the stars back (without the bloat).

[AstroNebulee]

19 minutes ago, happy-kat said:

Another idea would be to process the image and using Heal create a star less image to process the nebula. Then start again and using develop a conservative stretch for the stars mask and save (the pdf manual has how to use Heal module for starless image may need a couple passes), then use the Layer module to combine the stars back (without the bloat).

Thank you, it did cross my mind about creating a starless and separate stars image to see if that could help, thank you plenty to try out over the weekend 👍

[symmetal]

Another option AstroNebulee is to try an Astronomik L3 UV/IR cut filter in place of your Zwo one though it's a bit pricey for the 2" one. The L3 cuts off the shorter blue wavelengths which is a main cause of blue star bloat on less than perfect optical systems.

Alan

[AstroNebulee]

8 hours ago, symmetal said:

Another option AstroNebulee is to try an Astronomik L3 UV/IR cut filter in place of your Zwo one though it's a bit pricey for the 2" one. The L3 cuts off the shorter blue wavelengths which is a main cause of blue star bloat on less than perfect optical systems.

Alan

Thank you for the suggestion, sadly way out of my price range but maybe when funds allow I'll look into it 👍

[happy-kat]

Another is the yatton yellow #13 I think though I've never tried it. 

[AstroNebulee]

8 minutes ago, happy-kat said:

Another is the yatton yellow #13 I think though I've never tried it. 

It could be a number 12 yellow on a quick Google search but probably wrong, I was advised of a ir uv cut filter for use with my 294MC pro so that's what I bought, maybe these dont help the CA but then my 72ed is a low end scope 😞

[AstroNebulee]

I have been trying all weekend to get some sort of workflow sorted for this issue. I have also been reading a lot in the star tools forum and realise the stars aren't meant to be this way rather than blobs. 

Theses are very roughly processed and not had the final tweak in photoshop but I'm much happier with these. 

I'll post a screenshot of my scribbling workflow if anyone can decipher it. There are two examples one using an extra shrink module with halo extend and one with using the flux module and noise. It still needs a tweak here and there but I'm much happier now. 

Edited March 22, 2022 by AstroNebulee

[happy-kat]

Interesting, I'll look again when on desktop. I take it you processed as OSC and didn't split the channels to get at the blue directly.

Thanks for sharing your scratch pad.

[AstroNebulee]

10 hours ago, happy-kat said:

Interesting, I'll look again when on desktop. I take it you processed as OSC and didn't split the channels to get at the blue directly.

Thanks for sharing your scratch pad.

Yep I wanted to try as osc first to see what could be achieved. It was easy removing the purple /blue fringing. 

I used the repair module to reshape the stars as I have an eggy issue (maybe I can fo away with the repair as SV decon does a pretty good job and I've hopefully sorted the back spacing in the camera better) But if I didn't use the repair module the edges of the stars looked better. 

To remove the grey halo around the star core I wert back into filter created the mask for stars and then chose 'nudge screen' and clicked the grey halo part which lightened it. 

Then I'm trying to soften the edges of the halo, the inage using the extra shrink worked best, still a lot of playing about to do but progress made I think. 

If you can decipher my scratch pad good luck haha, the other side is worse. It will need a touch of tweaking but the body of it is there now. 

Reading the notes in the manual, synth module may be my friend here to help the edges of the stars. 

👍

Edited March 22, 2022 by AstroNebulee

[AstroNebulee]

Had another quick tweak tonight, basically moved the entropy module up, used the synth module and then used the second shrink module as a final step. Not sure where the purple hue has come from (looked good on the laptop) but yet to tweak in photoshop, but ok I think. Also reduced the green bias slider in colour module. 

Edited March 22, 2022 by AstroNebulee

[happy-kat]

That's pretty good at disguising that there was any chromatic aberration there at all.

Edited March 22, 2022 by happy-kat

[AstroNebulee]

11 minutes ago, happy-kat said:

That's pretty good at disguising that there was any chromatic aberration there at all.

Thank you 😊, I really think reading into the star tools software helped me understand the different uses of the modules better and that the stars aren't supposed to be just blobs. it just needs a star reduction on it and in photoshop I can alter the purple easily with a colour balance on the stars. 

The nudge screen in the filter module was a very useful tool after using the fringe killer and the synth module (settings for my scope). 

As I said before it looked so much better on the laptop than on devices. 

Edited March 22, 2022 by AstroNebulee

[happy-kat]

Could try (for purple stars), layer module invert foreground purple turns green, go to colour module cap green 100%, layer module invert foreground.

Edited March 22, 2022 by happy-kat

[AstroNebulee]

19 minutes ago, happy-kat said:

Could try (for purple stars), layer module invert foreground purple turns green, go to colour module cap green 100%, layer module invert foreground.

Thank you, I shall give that a go moro, before I hopefully can get the scope out, first in a long time.