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DDP star bloat

Posted: 06 Feb 2023, 14:04
by Morten Lerager
Hi'
How can i prevent star from bloat.
If I have a stack in a 16bit fits with stars up to 55-60000 they
become greater than 16 bit after a DDP.
When saved to 16bit most of the stars are 65535.
The only way I know to do this, is by carefull curve raising. ( not so good )
Or using "Normalised Tone Stretch" in Affinity Photo.
How do i approach this in AstroArt 8.

Regards Morten Lerager.

Re: DDP star bloat

Posted: 08 Feb 2023, 22:35
by fabdev
Hi, it's not easy to reply without seeing the actual image. By the way, you could use the StarNet plugin to apply DDP only on the nebula and not on the stars:

1) Duplicate the image, let's call it "B".
2) Apply your DDP on image "A".
3) Apply a DDP with low gamma and mid white point to image "B" (so that stars are not bloated)
4) Remove stars in "A" with Starnet plugin.
5) Duplicate "B" let's call it "C".
6) Remove stars in "B" with Starnet plugin.
7) Subtract from "C" the image "B" to create a stars image.
8) Add to "A" the stars from "C".

Greetings, Fabio.

Re: DDP star bloat

Posted: 09 Feb 2023, 19:35
by Morten Lerager
Hi Fabio.
I was hoping for some solution with stretch without clip.
I already use starnet for narrowband nebula and merge the stars from broadband.
Thank you.