Fringe and halo killer

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Fringe and halo killer

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If you acquire your data with a achromat refractor, your data may be suffering from the purple halo effect (chromatic aberration). There is a very quick and easy way in StarTools to get rid of the purple/bluehish fringes, from where you can further reduce any halos using the 'Magic' module.

You can go from this;
megrez_m42.jpg
megrez_m42.jpg (98.62 KiB) Viewed 7795 times
To this;
megrez_m42_fringekiller.jpg
megrez_m42_fringekiller.jpg (96.36 KiB) Viewed 7795 times
To attack the purple fringes, simply launch the 'Filter' module;
img2_004.jpeg
img2_004.jpeg (102.94 KiB) Viewed 7796 times
Click Mask, and create a star mask that is suitable. You'll want to include anything that is very bright and/or over exposed, i.e. anything that can cause the chromatic aberration to be prevalent;
img2_005.jpeg
img2_005.jpeg (171.04 KiB) Viewed 7796 times
Next, back in the 'Filter' module, set 'Filter Mode' to 'Fringe Killer' and 'Filter Width' to '1' (the latter lower value makes the filter more responsive to colours that are close - but not exactly the same - to the ones you click). All you have to do now is zoom into a star that exhibits the chromatic aberration and click on the offending halo.
img2_006.jpeg
img2_006.jpeg (70.14 KiB) Viewed 7778 times
After clicking a few times, this is the result;
img2_007.jpeg
img2_007.jpeg (69.48 KiB) Viewed 7796 times
Ivo Jager
StarTools creator and astronomy enthusiast
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