Found the following by accident, but you can quickly make great results in Gimp 2.9 (a free program) to put the final touches on your stacked astrophoto. Even a very faint object can look great with this method.
- First, output your astro photo from your Stacker program (like DSS) to a TIFF file ( i use an OSC, just one full-color file). So, Stack your multiple shots before doing the following.
- Open the output/stacked file with Gimp 2.9 or later (2.8 won't open that kind of TIFF)
- Choose Colors
- Choose Levels (not Curves) -- this method is quicker and easier than the Curves method
- You are on the "Adjust Color Levels" pop-up screen.
- Look under where it says "All Channels" on this pop-up screen.
- Push the "Auto Input Levels" button from the middle of this pop-up screen titled "Adjust Color Levels". This will make an immediate improvement to your image -- its like a little bit of magic. But you can do a little more.
- Look to the right of this button, you'll see 3 droppers, one black, one gray, one white. Choose the black dropper.
- Then move this dropper into the area that's supposed to be black say outside of your central/object of attention AND click. This makes what's supposed to be black actually black. You can do it more than once if needed in different areas that are supposed to be black.
- Then if you want to enhance further you can try this (optional, only if you like the result):
- Under the Input Levels (at the top of the pop-up), pull the white triangle from the far right, pull it left, until your image is further enhanced (skip this if you don't like it).
Then output your result as a png:
- Select File,
- Export As
- Give it a file name with .png (or .jpg) extension
- Push Export. (your original TIFF is still safe/ unedited)
I've attached screen-prints (not actual original files) of the before / after of the Horsehead nebula region.
Edited by Foobaria, 03 February 2018 - 06:28 PM.