horizontal lines in st8

Discussion in 'Legacy Models - Community Support' started by akihiko yamada, Aug 15, 2020.

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  1. akihiko yamada

    akihiko yamada Standard User

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    I focused a st8 attached to F13.8/D300mm makstov with a celestron 0.63x reducer and a cfw10 using a ccdsoft after a long telescope vacation in my remote observatory.

    The shutter speed was set to 0.001sec, 2x2binned, the images showed defocused,decentered ones.
    Then I captured several images by changing the focus position,and several shutter speed up to 10sec.
    All images showed a full of horizontal lines across the frame where there were only 2 lines analyzing histograms from a stella image of Japan,

    the level of one line is 50627,the other line is 50692 in all images. I confirmed the carousel rotated and controlled through ccdsoft,ccdops and sbigcontrol.
    The minimum shutter speed of a st8 is 0.12sec due to a mechanical shutter, 0.001sec seems to convert automatically 0.12sec.
    This problem occurs in ccdops and sbigcontroll,

    What is the cause of this phenomena? The ccd censor is failed or the mechanical shutter is in trouble?
     
    akihiko yamada, Aug 15, 2020
    #1
  2. Colin Haig

    Colin Haig Staff Member

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    The minimum shutter speed for the ST-8 is 0.11 seconds. That is for a camera in perfect condition. The shutter motor may not move that quickly since it is very old. 0.12seconds is probably the correct minimum speed for that camera. It does not go faster. This is not a video camera - this is a long exposure astronomy camera.

    Please send a FITS image from the camera. Use the "Upload a File" button at the lower right. Make sure the image is binned 1x1, and that the exposure is longer than the minimum.
     
    Colin Haig, Aug 15, 2020
    #2
  3. akihiko yamada

    akihiko yamada Standard User

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    I took 1x1 images, but, ccdops and ccdsoftware could not download images because these software did not responde during downloading, both software are ok for 2x2, so the attatched images are 0.12 and 1.0sec exposure and corresponding dark frames via sbigcontrol.
     

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    akihiko yamada, Aug 16, 2020
    #3
  4. Colin Haig

    Colin Haig Staff Member

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    Is this an ST-8XME USB camera? What is the serial number?
    Put the camera on its own USB connection directly to a USB port on the back of the computer.

    Please make sure to use the SBIGDriver Checker and CCDOPS from this web page:
    https://diffractionlimited.com/legacy-product-support/

    I am not familiar with Manfred Schwartz's SBIGControl program that you used.
    You could also try the MaxIm DL Pro demo.
    Go here, and click DEMO:
    https://diffractionlimited.com/maxim-dl/

    I think you have a camera hardware problem.
    Check the camera cables are in good condition and connected correctly.
    Check the power supply is putting out the correct voltages.
    All pixels are at 51143.
    Have you tested to see if the guide sensor works?

    It will probably have to go to @Bill for repair.
     
    Colin Haig, Aug 16, 2020
    #4
  5. Doug

    Doug Staff Member

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    That does look like a hardware failure.

    We have very limited ability to fix cameras that are that old - all of the parts in it are obsolete.

    You might want to contact @Bill at SBIG Service and Repair, to see if he can do anything for you.
     
    Doug, Aug 16, 2020
    #5
  6. akihiko yamada

    akihiko yamada Standard User

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    Thank you for your advice, I"ll contact Bill.
     
    akihiko yamada, Aug 18, 2020
    #6

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