Thread: Omega the Great
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Old 29-04-2008, 08:23 AM
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strongmanmike (Michael)
Highest Observatory in Oz

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Join Date: May 2006
Location: Canberra
Posts: 17,689
Quote:
Originally Posted by tornado33 View Post
plenty of resolution there. What was the cause of the random noise issue in the camera? Was it a shielding issue? In some DSLRs some reports of banding was traced down to EM radiation from autofocus lens motors and electronics
Scott
It was a clocking issue, my chip had been incorectly clocked for some reason, this meant that there was what appeared to be noise/hot pixles that varied from frame to frame so removing them with darks was impossible, I had to dither guide which I had to do manually (ie move the scope a bit after every sub) as I use a seperate guide camera to the imaging camera (my camera control software doesn't support this capability automatically). I then median combined my subs which worked well but manually moving the scope a few pixels after each sub was annoying, also median is not the ideal combinatioin method if you can avoid it. FLI gladly rectified the problem free of charge in a 3 week turn around last year and now I don'y dither anymore and I can use the "add" command in preprocessing instead of median which is a better combination method IMO. At -35 the downloaded raw subs are very clean now.

Mike
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