When using the zoom notice that my camera refracted the light.
That I can use to correct this?
In darktable there are two tools:
- chromatic aberration and defringe - just try it (works great within physical limits).
see: https://www.darktable.org/usermanual/ch03s04s04.html.php
Try this GIMP script
http://www.farcrydesign.com/GIMP/PurpleFringe.html
When you want to do something with the gimp google gimp what ever you want to do. The above came up from gimp fixing chromatic aberration. There may be others and other ways of doing it.
John