STX 16803 problem

Discussion in 'STX and STXL' started by Max Mirot, Oct 28, 2019.

  1. Max Mirot

    Max Mirot Cyanogen Customer

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    I have too problems. Not sure they are related.

    The first problem is dark horizontal lines extending from bright stars

    You can see this in the stacked OIII image. There is also smearing of hot pixels horizontally in the dark that I suspect is part of the same problem.
    ---------------------------------
    My second issue is that I noticed a varying background noise in my NB images.

    I made a FFT of the read noise by subtracting a master bias from a single bias. It produced the last image showing a non-random pattern consisting of thin vertical lines.

    Please help

    Thanks

    Max Mirot
     

    Attached Files:

  2. Max Mirot

    Max Mirot Cyanogen Customer

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    Apparently the last two images are not stretched. Ignore them for now

    Thanks
     
  3. Max Mirot

    Max Mirot Cyanogen Customer

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  4. Max Mirot

    Max Mirot Cyanogen Customer

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  5. Max Mirot

    Max Mirot Cyanogen Customer

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    Here is first image again

    Light_frame.jpg
     
  6. Doug

    Doug Staff Member

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    Please provide raw FITS frames.
     
  7. Max Mirot

    Max Mirot Cyanogen Customer

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  8. Doug

    Doug Staff Member

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    The background should not be an issue. If calibration is done correctly it will subtract out.

    I am more concerned by the trails behind the stars. Can you supply the light frames?
     
  9. Max Mirot

    Max Mirot Cyanogen Customer

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  10. Doug

    Doug Staff Member

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    I'm not seeing anything like the streaks in your first light image. Was that a single frame? Do you have the raw FITS file for that frame?

    What is your camera serial number?
     
  11. Max Mirot

    Max Mirot Cyanogen Customer

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    I must be not understanding.
    These are raw fits taken with MaxIM DL.
    They have not been calibrate or altered by software unless I picked the wrong directory.

    I am not at home so I don't have the Serial number handy. I will it get tonight

    Max
     
  12. Colin Haig

    Colin Haig Staff Member

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    Max - I just had a look.
    The Light_frame.jpg is a JPG subframe of an image, and the OIII and Ha images you provided are of a wider field, centred pretty much on the same thing, but there is no evidence of a problem. So, we're looking for the images that you used to produce the light_frame.jpg.
     
  13. Max Mirot

    Max Mirot Cyanogen Customer

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    Thanks as soon as I get home. I will upload them
     
  14. Max Mirot

    Max Mirot Cyanogen Customer

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    The light frame JPG is intergration of over a hundred images in PI
     
  15. Max Mirot

    Max Mirot Cyanogen Customer

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    Sorry.
    This is definitely a Pixinsight processing problem.

    I will let you know more when figure it out.

    Thanks

    Max
     
  16. Max Mirot

    Max Mirot Cyanogen Customer

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  17. Max Mirot

    Max Mirot Cyanogen Customer

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  18. Colin Haig

    Colin Haig Staff Member

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    Max - good talking to you today.
    Turn on RBI preflash in MaxIm, and I expect that will clear up the few ghost images in that last frame.
    I suspect the processing tool to remove the ghosts in PixInsight is causing a bit of that effect you are having.

    The Cloudynights issue looks like a trailing charge problem with QHY cameras (known issue with them). From my experience, the SBIG STXL-16200 and another manufacturer (non QHY) don't have those artifacts.

    In short, turn on RBI, and then see how you make out.
     
  19. Max Mirot

    Max Mirot Cyanogen Customer

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    thanks for all your help.
    max
     

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