Resolved Banding on the lower half of images

Discussion in 'Legacy Models - Community Support' started by Timo Nordberg, Feb 16, 2020.

  1. Timo Nordberg

    Timo Nordberg Standard User

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    Hi !
    I have an old ST2000XM from around 2004 and from last year the images have banding on the lower half.
    please see the attached image.
    I have seen somea threads here concerning banding but I´m not shure the answers apply to my camera.
    Can the source be a bad usb cable ?
    ngc891comb3img.JPG
    Regards
    Timo Nordberg
     
  2. Colin Haig

    Colin Haig Staff Member

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    The old cameras are USB 1.1 and don't have frame buffers, so need a quality USB cable, preferrably directly connected to a dedicated port on the computer that is not shared with other USB devices.
    Can you post a FITS image? Perhaps a bias and dark as well.
     
  3. Timo Nordberg

    Timo Nordberg Standard User

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    Hi Colin !

    Next time clear skies appear I will test a new quality usb cable.
    I enclose a FITS img. Dont have bias or darks for the moment.
    Thank you for taking your time with your reply to my question :)
    Rgds
    Timo
     
  4. Timo Nordberg

    Timo Nordberg Standard User

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    And here is the FITS file.
     

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  5. Colin Haig

    Colin Haig Staff Member

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    You've processed the image, so I can't tell what's going on. The only thing I see is a bit of a thermal gradient and some vertical column noise.
    Since the camera is 16+ years old, the capacitors in the camera and the power supply will have degraded (this is normal for all electronics) and this might account for some of what is going on. I'd really like to see a bias and maybe a 1 minute dark.
     
  6. Timo Nordberg

    Timo Nordberg Standard User

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    Thanks for your reply Colin !
    I´ll take a bias and a 1 minute dark tonight :)
    Timo
     
  7. Bob Denny

    Bob Denny Cyanogen Customer

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    He may also have a computer that is doing something else while downloading the image. If the CPU is “stolen” from MaxIm during image downloading the rate of transfer will vary and... banding. Those old unbuffered cameras are seriously painful.

    Along with Colin’s primary advice, also check to see that nothing at all else is running on your PC while you are imaging. This includes automation programs like CCDC, SGP, CCDAP*. Also there may be a “priority” setting for that camera in MaxIm. Set it to High. In the past at least, this would force MaxIm to set its CPU priority high and lock out other software during an image download.

    I hope I am not overstepping my boundaries here.

    * If you Are using ACP it’s OK to let it run, it knows about this and puts itself to sleep during image downloads.
     
  8. Doug

    Doug Staff Member

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    That’s all good advice, Bob.

    There is a high probability that download interruption from other programs is the cause of the problem. Our modern cameras do not have this problem because they have frame buffers.
     
  9. Timo Nordberg

    Timo Nordberg Standard User

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    The ST2000XM connected to CCDOPS is whats running on the laptop. No other programs or devices in other usb ports.
    I enclose 2 bias img. and 1 dark img. 60 sec.
    What is your opinionof these ?
    Rgds
    Timo
     

    Attached Files:

  10. Timo Nordberg

    Timo Nordberg Standard User

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    I use CCDOPS for simple imaging and APT or SGP for advanced imaging and sequencing. But always only one program and one device
    at the same time :)
    Timo
     
  11. Doug

    Doug Staff Member

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    Those three images look just fine.
     
  12. Colin Haig

    Colin Haig Staff Member

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    All good, no issues.
     
  13. Timo Nordberg

    Timo Nordberg Standard User

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    Thanks for all help !
    With a new usb cable I got an image can see here below :)
    Regards
    Timo
     

    Attached Files:

  14. Colin Haig

    Colin Haig Staff Member

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    Looks nice and clean. Have fun with your imaging!
     
  15. Timo Nordberg

    Timo Nordberg Standard User

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    Thank you Colin :)
     

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