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Auto star shrink

Posted: Wed Nov 18, 2020 3:32 pm
by arrowspace90
If I try to use the auto shrink for stars in this RGB image, will the mask protect the background elements of the galaxy, or will the stars in M33
be shrunk as well?
Obviously I don't wish the latter, so would I need to manually pick stars to shrink to be safe? The large yellow ones are the main culprits when seen at a higher resolution and there aren't all that many of them.

Re: Auto star shrink

Posted: Wed Nov 18, 2020 7:15 pm
by happy-kat
You create the mask you want on the stars you want, you have the control

Re: Auto star shrink

Posted: Fri Nov 20, 2020 5:01 pm
by arrowspace90
right. I don't know how to do that.

Re: Auto star shrink

Posted: Fri Nov 20, 2020 5:36 pm
by arrowspace90
In the example below, I just want to shrink some of the bright, bloated stars.
But when I try the auto method, the galaxies in the group are green along with the stars.
I have tried several times with a lasso mask to circle the problem stars, or to circle the galaxies. But I can't figure out
how to tell Star Tools to shrink ONLY the stars and leave out the little galaxies.
Can someone tell me simply what the steps are?
Yes, I stipulate I am dumb to not know how to do this.

Re: Auto star shrink

Posted: Fri Nov 20, 2020 7:19 pm
by arrowspace90
So here, I have got masks over mostly just the stars I want to shrink with the little galaxies excluded. Looks like it would work but...

what do I do now? If I press the obvious "shrink" tab, the green masks shrink, not the stars. So this is where I am stuck. I could do this backwards, and
just mask the galaxies, perhaps that's more correct. But then, same thing, how do you execute the shrink to actually happen?

Re: Auto star shrink

Posted: Fri Nov 20, 2020 10:56 pm
by almcl
Don't use the 'Shrink' button within the mask module - that's for changing the size of the mask.

To change the size of the stars, having created your mask, 'Keep' it and then, when back on the main page, select the Shrink button there:
shrink.jpg
shrink.jpg (24.33 KiB) Viewed 2878 times
Here's what I got when operating on your image above, not perfect by any means, but have a play with the iterations and other parameters in the Shrink module:
Untitled-1.jpg
Untitled-1.jpg (57.27 KiB) Viewed 2877 times

Re: Auto star shrink

Posted: Sat Nov 21, 2020 3:21 pm
by arrowspace90
Thanks.
Of course I was using the "Shrink" tab. I didn't try iterations, so I will do that. What you did is an improvement. I read that SCTs and RASAs like mine are prone to bloated stars and halos.