Star control

Questions and answers about processing in StarTools and how to accomplish certain tasks.
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Rkonrad
Posts: 247
Joined: Sun Feb 07, 2016 2:55 am

Star control

Post by Rkonrad »

Hi

I'm part of the dslr_astro_image_processing group on yahoo. They provide sample images and advise as how to improve processing. There's not many who use Startools and the moderators have advice mainly relating to photoshop or images plus. I've been working one one particularly fine piece of data ldn1235 (dark shark) taken by Scott Rosen http://www.astronomersdoitinthedark.com/. I'm having some difficulty controlling stars buts that's a broad question. I've attached the image which I think is my best effort so far.

When do the deconvolution I'm finding it difficult to mask (invert) the star I want. You'll notice that the medium sized coloured stars with nice halos have ugly rings. So I only want to select the smaller stars. I'm also finding when I shrink the stars more than a pixel, the stars very quickly lose cohesion and also darken. I tried sharpening them but that just increases their size again. Thanks for your help!
Rkonrad
Posts: 247
Joined: Sun Feb 07, 2016 2:55 am

Re: Star control

Post by Rkonrad »

For some reason the attachment didn’t come through.- ah too big. For this post to make any sense you have to see a lot of detail so I'll post a flickr link.

Image
shark by richard_konrad, on Flickr
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admin
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Re: Star control

Post by admin »

Hi,

It's a little tricky to give advice without being able to see the data...
The Decon module, courtesy of the AutoMask feature should have created a decent mask to start off with. Was that not the case?
The image you posted suggests no mask was used at all, which causes ringing, while in turn, the Shrink algorithm in the Magic module will start drawing in the ringing, rather than the halo...
Ivo Jager
StarTools creator and astronomy enthusiast
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