fringe killer filter add blue back to central star

[alacant]

Forgot. Not sure if this is relevant or even whether it makes a difference: LRGB b. I set Channel Interpolation to 'off'. The stars appear blue and the decon seems more effective, but this maybe my screen or eyes or imagination... Not enough hours in a day.

[happy-kat]

Great helpful thread.
I have been using the decon method but have found it works for me better if I do the following.
(I have copied Ivo's text changed/added to it)
--- Bin
Parameter [Scale] set to [(scale/noise reduction 50.00%)/(400.00%)/(+2.00 bits)]
I binned the image to 50% and saved it.

--- LRGB
Click "blue" to load only the blue channel of the file we just saved. The other channels will be automatically set as well due to "Channel Interpolation". So you end up with a b&w representation of the blue channel.

--- AutoDev or Develop
So we can see what we're doing (we'll be undoing this stretch later on using the "restore" functionality).

--- Mask
Star mask plus galaxy area if appropriate.
Invert mask.
Save mask

--- Deconvolution
Parameter [Mask Behavior] set to [De-ring Mask Gaps, Show Result]
Parameter [Radius] set to [11 pixels] (worked for me on my image)
Parameter [Iterations] set to [1]
Planetary

This method for me meant I kept the star colours and just dealt with the awful blue halo bloat over spill.

Now you can use StarTools' unique "Restore" functionality to restore the data to a state where it is unstretched (so we can merge it with the unstretched red and green channels), but with deconvolution still intact (the Restore functionality is a perk of the Tracking feature of StarTools, allowing you to "time travel" and pick and choose aspects of the image you like - an "undo" feature on steroids). We choose "linear, wiped, deconvolved".

Save the image.

Now use the LRGB module again to load the red and green image from the 50% binned (but otherwise untouched) image, and load the image we just saved as the blue image.

You should now have an image with a (somewhat) better focused blue channel.

From here, you can use process the image.
I used manual dev, wipe, contrast, manual dev, colour (with mask created before), flux (mask just on galaxy), denoise (with inverted star mask)

Bin 75% created less satisfactory final result.
Canon 1100d vintage 1973 200mm lens.
Virtuoso Alt Az tracking mount.
3 street lights one so overhead 20 feet from lens that I had strong light pollution plus heavy chromatic aberration to deal with.
79 light files (mainly 30 seconds plus a few 20 and 45) flats, dark flats.
I found bias on testing did not help this image.
Hopefully you can see the image OK as my monitor calibration doesn't work for everyone.

M101 Pinwheel

NewLRGBComposite bin50 v3.2.jpg (452.38 KiB) Viewed 16464 times

[happy-kat]

I drizzled the stack x2 and then used the 35% bin.
Just processed again. It looked fine in StarTools but the tiff in PaintShopPro didn;t look as goos but needed to use it to save as jpeg. anyway just sharing I am happy this approach is dealing with the CA.

NewLRGBComposite v5.1.2.jpg (501.35 KiB) Viewed 16459 times

[happy-kat]

An example of the CA in the source lights of this image.

CA example.jpg (456 KiB) Viewed 16459 times

[admin]

Thanks for sharing!

[happy-kat]

I kept processing from scratch as I was not happy with the colour on M101 got what I wanted eventually. As my exposures were not long enough to truely capture the colour I prefer this version. Deconvolution provides a much better result then the fringe killer for dealing with the star shapes but does need the use of masks. They are great tools and when referencing the star log it makes it easier to recreate work flows.

Please for a future version of StarTools could we add to the star log when a mask was used, saved and opened within the workflow.

NewLRGBComposite bin50 v11.2 cp.jpg (335.29 KiB) Viewed 16439 times

[admin]

I kept processing from scratch as I was not happy with the colour on M101 got what I wanted eventually. As my exposures were not long enough to truely capture the colour I prefer this version. Deconvolution provides a much better result then the fringe killer for dealing with the star shapes but does need the use of masks.

Per-color-channel decon is indeed really the proper/ultimate way of fixing this type of of chromatic aberration. It's fixing/refocusing the light at different wavelengths, directly tackling the cause of the chromatic aberration. I'm really happy this works well for you!

Please for a future version of StarTools could we add to the star log when a mask was used, saved and opened within the workflow.

The latest 1.4.x versions log a lot more events, including mask import/export. User Guy (from the excellent User Notes) has been working on a scripting tool using those more detailed logs. I'm hoping to find some time in the next couple of days to check it out!

[happy-kat]

That sounds really great about the log file and scripts, though I am using 1.4.327 and the log has no mask activity of save and open in it.

[admin]

Try the 1.4.332 version.

I got to play with user Guy's handiwork - it's pretty cool! I hope he releases it soon.

[happy-kat]

Sorry about opening this old post, but I tried the trick I did in this post (by happy-kat » Sun Apr 22, 2018 8:24 pm) using 1.6.686 and I could not get the same effect correction on the stars, I was using other data. and in the Decon module I see there's been a change in naming. Previously
Parameter [Mask Behavior] set to [De-ring Mask Gaps, Show Result]
Is this the same as Enhanced Deringing and if the slider is to the left is that same as the previous [De-ring Mask Gaps, Show Result] please?