Problem with fixed pattern noise (banding) with my ATIK 383(mono)

[Claus]

Hello Astronomers 

I hope someone can help me with my problem. I own an ATIK 383 (mono) camera and got a problem with the so-called "fixed pattern noise". The camera is about 5 month old. As shown on the picture below there are vertical stripes from top to bottom, which concern only about 20% of the right half of the image. The image there is a stack of 20 lightframes, edited with Pixinsight. What I've already tried or analyzed:

- Problem exists, no matter if I am using a constant voltage of 12,5v, 13v or 13,5v für the camera
- Problem concerned all filters
- The Problem is always on the right half, no matter how the camera is rotated to the filters or telescope within the image train
- Even with a very large stack of BIAS (300 x) and DARKS (60 x), i am unable to eliminate the stripes. I could reduce it much more with a large stack of calibration frames, but as soon as the final image is stacked and then stretched the stripes come out. Sometimes more, sometimes less.
- I also tried FLATS with a different median ADU (5000,10000,20000,30000 and so on) without success.
- I also doesn't matter how long the exposures are, 5min, 10min, or 15min.


Is the camera faulty, or are these noise patterns and banding in the "normal" range after calibration? Where could be the problem or what could I try else?


kind regards
Claus





 

[scirocco1]

Hello sorry to hear that. I have the same problem too (example: http://www.astrophoto.ro/tmp/C2014Q2_20150113.jpg)
Sometimes is ok though (http://www.scirocco.ro/tmp/crescent_18x600s.jpg) I didn't figure out a pattern yet.
I hope we can discover a workaround.

[Chris]

I've heard it suggested that these cameras are a bit sensitive to low voltage, even slightly lower than 12V.  I've not seen it myself but maybe that would be a clue.

Chris

[scirocco1]

I used different voltages, from 12 to 13.8V, now I run 12.5V from some time with mixed results (sometimes works fine, sometimes no. everything is the same - is mounted in a fixed observatory, so I don't know the culprit yet, maybe in the timing of the acquisition of the calibration frames?