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federico bonino
member


Reged: 06/21/12

Loc: Argentina
Problems with dark lines new
      #6178770 - 11/06/13 08:36 AM Attachment (11 downloads)

Hello everybody!

I have a problem when I take videos with NEXIMAGE CCD. In all cases appear some dark lines that is very difficults to remove.
I have seen that it is possible to minimize them by adjusting the tuning, but not possible to eliminate them.

Could any one told to me if this is a normal effect?
How is the procedure to eliminate them?.

Thanks to all
I attached an image like example
Federico


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Tapio
Pooh-Bah


Reged: 09/24/06

Loc: Tampere, Finland
Re: Problems with dark lines new [Re: federico bonino]
      #6178820 - 11/06/13 09:13 AM

I guess you are suffering from Newtons rings.
Two ways for cure
1. Tilting
http://zwoug.org/viewtopic.php?f=24&t=1395
2. Flat fielding
http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/4999954/Main...


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bunyon
Post Laureate
*****

Reged: 10/23/10

Loc: Winston-Salem, NC
Re: Problems with dark lines new [Re: Tapio]
      #6178884 - 11/06/13 09:56 AM

Yes, that looks like Newton's rings. I cured the ones in my system by purchasing a tilt-adjuster from OPT. If they aren't bad, flat fielding may work. You might play around trying to manually tilt the camera to see if you can get rid of them.

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federico bonino
member


Reged: 06/21/12

Loc: Argentina
Re: Problems with dark lines new [Re: Tapio]
      #6178913 - 11/06/13 10:11 AM

OOHHKEY Tapio!!!! Excellent!!! Thnaks very much!!.

I did not know that such problems exist.

So Them If I understund good, the problem is due to a difference of parallelism between the camera chip and the device of PST Them maybe I should check first the condition of setting between the diagonal & CCD.....

OK OK thanks very much by your usefull help!!
Best Regrads
Federico


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federico bonino
member


Reged: 06/21/12

Loc: Argentina
Re: Problems with dark lines new [Re: bunyon]
      #6178952 - 11/06/13 10:35 AM

OK Paul Thanks!!

OK so them, I start trying moving the camera, them if I donīt eliminate it, I try with flat frames.

Thanks a lot!


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Paul Hyndman
sage


Reged: 07/13/04

Loc: Connecticut Shoreline USA
Re: Problems with dark lines [Re: federico bonino]
      #6179864 - 11/06/13 07:17 PM

Take care to ensure the camera is solidly mounted (droop-free), as even a miniscule variation from square (orthogonality) can introduce the "rings". As Tapio mentioned, a tilt adapter can help dial them out, if finessing the mounting alone does not do it.

My preference has always been to hone "front-end" techniques that improve the quality of the raw images, thus requiring the least amount of post-capture processing "magic".

But hey... a big part of what makes this stuff so much fun is the challenge (and sharing our notes)!

Paul


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