Author Topic: Working with low SNR Images ...  (Read 1686 times)

Offline oo_void

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Working with low SNR Images ...
« on: 2013 January 04 09:57:39 »
Living in a very "urban" area, pulling in enough photons is always a challenge. Adding to that, at my dark sky site, I need to clear out by 2am, once again making it challenging to pull in enough good data. With such low SNR data, I'm having a lot of trouble using some of the more popular PI techniques that are intended for use on Linear data ... Deconvolution, ACDNR, etc. I've read a number of the challenges posted here, looking for some additional tips and tricks, but nothing seems to work with my data.

The main thing is that it appears there's little to no head room for many of the Deringing techniques that these processes use to minimize artifacts. That said, my "cookbook" is pretty limited to just DBE, Background Neutralization and Color Correction. The magic feature for me is the Masked Stretch script which is just about the only technique that I've found to be able to pull out something that even resembles usable data. Even then, I've had no luck with ACDNR and have had to move over to PS to for noise removal using some layer techniques. Unfortunately, that approach tends to lead to some harsh edges, making the stars look artificial.

Here's the best I can come up with --


Full size is here --
http://dl.dropbox.com/u/49984889/m13.png

And the original FITS file if someone wants to take a shot at it --
http://dl.dropbox.com/u/49984889/m13.fts

Offline Geoff

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Re: Working with low SNR Images ...
« Reply #1 on: 2013 January 04 15:00:04 »
If you're not getting enough data in one night, why not image the same object over multiple nights?
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Offline oo_void

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Re: Working with low SNR Images ...
« Reply #2 on: 2013 January 04 18:11:10 »
I have access to the dark sky site once a month, then fog to deal with in SF.