Orpington Astronomical Society

Astronomy => Astrophotography => Topic started by: Fay on Jul 18, 2010, 12:39:50

Title: Saving image after doing a star layer
Post by: Fay on Jul 18, 2010, 12:39:50
I have been processing trying out a star selection layer. Flattened the layers & left with just background, save it but it only saves as black,  no details.

Has anyone any idea what I am doing wrong?

Thanks
Title: Re: Saving image after doing a star layer
Post by: MarkS on Jul 18, 2010, 17:46:06

After you flattened the layers, could you see detail - did the pixels have values?  But you're saying the saved image had pixel values of zero?   That sounds very strange ...
Title: Re: Saving image after doing a star layer
Post by: Fay on Jul 18, 2010, 18:53:48
Mark, after flattening, it looked normal in PS. THere were two histograms. One was for the star layer. Even though I had deleted the duplicate layer & only the background one was still there.

When opened in Maxim or Astroart, the one that looks normal in PS, opens as  the star layer. Crawling ants etc around the stars.

I have done it 5 times & cannot get the final bit correct. Looks like the correct image will save but it saves a the star layer.

Being that there are 2 histograms on show, the star layer is still around somwhere.
Title: Re: Saving image after doing a star layer
Post by: Rocket Pooch on Jul 18, 2010, 19:24:25
Hi,

Whats a star layer?

Chris
Title: Re: Saving image after doing a star layer
Post by: Fay on Jul 18, 2010, 19:26:27
It enables you to elimiate the stars from any processing
Title: Re: Saving image after doing a star layer
Post by: Rocket Pooch on Jul 18, 2010, 20:01:09
oh ok, why would you want to do that?

chris
Title: Re: Saving image after doing a star layer
Post by: The Thing on Jul 18, 2010, 21:27:40
To be able to rescue star colours (inverse selection), apply curves etc to faint fuzzies without blowing out the stars and so on. Deep Sky Stacker can produce a star mask for just this purpose.
Title: Re: Saving image after doing a star layer
Post by: Fay on Jul 18, 2010, 23:18:43
Oh will try that Duncan
Title: Re: Saving image after doing a star layer
Post by: MarkS on Jul 19, 2010, 06:58:40
A star layer is also very useful to isolate stars from the rest of the image for adding diffraction spikes!
Title: Re: Saving image after doing a star layer
Post by: Rocket Pooch on Jul 19, 2010, 07:31:33
Hi Mark,

That makes perfect sense then :-)

Chris
Title: Re: Saving image after doing a star layer
Post by: Mac on Jul 19, 2010, 13:22:34
Are you using photoshop?
are you saving it for a final image?
if so, make sure the star mask is not selected and check that the layer you want to save is visable i.e. the eye on the side is showing.
sounds like you are saving just the mask.

sont forget to save is also as a pst so you can come back to it in photoshop, with all your layers ect.

Mac.
Title: Re: Saving image after doing a star layer
Post by: Fay on Jul 19, 2010, 15:18:13
Yes it does look like that Mac, although the background is what I want but the mask histogram is still sitting there, so it is around somewhere.
Title: Re: Saving image after doing a star layer
Post by: Mac on Jul 19, 2010, 16:21:45
can you post a link to the photoshop file ?

Might make it easier
Title: Re: Saving image after doing a star layer
Post by: Fay on Jul 19, 2010, 16:31:13
would not know how to do that Mac, it is on laptop anyway