Resolved Image artifact after camera was knocked against mount

Discussion in 'Legacy Models - Community Support' started by Anthony Bailey, Apr 20, 2020.

  1. Anthony Bailey

    Anthony Bailey Standard User

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    Hi all,

    I was putting my scope with my camera attached on the mount last night & I managed to knock the camera against the tripod leg. It wasn't a brutal blow but a sharp knock nonetheless. After connecting the camera I ran Nebulosity IV in frame & focus mode and noticed a bright glow in one corner of the frame which quickly spread to about half the frame as shown in the attached images. I took a 30 second exposure without cooling at the ambient temp. of 15 degrees Celsius as attached. Camera is an ST8300 C. Any ideas on what I might have done?
    Thanks in advance,
    Tony
     

    Attached Files:

    Anthony Bailey, Apr 20, 2020
    #1
  2. Doug

    Doug Staff Member

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    That looks optical in nature. Check for correct shutter operation, light leaks (e.g. a gap somewhere letting light in, etc.). Check adapters and the telescope ahead of the camera.

    What do your dark frames look like?
     
    Doug, Apr 20, 2020
    #2
  3. Anthony Bailey

    Anthony Bailey Standard User

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    Hi Doug,

    thanks for the quick response. I'm somewhat relieved by your reply. I shut the camera down as soon as I noticed it so I don't have any darks from last night.
    I opened the housing to have a look at the sensor & check for any other obvious damage. Everything looks perfectly normal. I also replaced the desiccant while I was at it, which was due but not
    causing any problems. I could put the camera on a scope & shoot some darks except I've had the chamber window off briefly to change the dessicant. Do you think this would be a problem?
    or best not to & wait 24hrs.
    Cheers,
    Tony
     
    Anthony Bailey, Apr 20, 2020
    #3
  4. Bill

    Bill SBIG Service and Repairs Staff Member

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    What model camera? It has that look that is sometimes seen with shutter problems. As long as you don't cool the camera, you can take some test images...

    -Bill
     
    Bill, Apr 20, 2020
    #4
  5. Anthony Bailey

    Anthony Bailey Standard User

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    It's an ST8300C Bill & thanks for your input, I'll set it up & take some darks without the cooling.
    Cheers,
    Tony
     
    Anthony Bailey, Apr 20, 2020
    #5
  6. Anthony Bailey

    Anthony Bailey Standard User

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    View attachment 7239 View attachment 7240

    Here are a couple of test images. 1 x 60 second dark & 1 x 1/10th sec light frame shot in a darkish room.
    I took a series of ten lights & they all looked very similar so the shutter seems to be working as it should.
    I guess the issue must have been light leaking into the image train as Doug suggested. Would you guys agree
    based on the test images?
    Cheers.
    Tony
     

    Attached Files:

    Last edited: Apr 20, 2020
    Anthony Bailey, Apr 20, 2020
    #6
  7. Doug

    Doug Staff Member

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    Please upload FITS images. Can't tell anything from JPEG.
     
    Doug, Apr 21, 2020
    #7
  8. Anthony Bailey

    Anthony Bailey Standard User

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    Sorry Doug, fits are attached. The dark frame was binned & resized to reduce the file size to make the upload possible. Also, what would be the minimum amount of time to wait before cooling can be used after changing the desiccant?
    Thanks again,
    Tony
     

    Attached Files:

    Anthony Bailey, Apr 21, 2020
    #8
  9. Doug

    Doug Staff Member

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    Your images look like normal dark frames.

    It would be a good idea to detach the camera from the telescope, and observe the operation of the shutter while taking an exposure.

    Instructions for desiccant recharge, including waiting time, are on page 48 of the STF user manual: https://diffractionlimited.com/downloads/STFUserManual.pdf
     
    Doug, Apr 21, 2020
    #9
  10. Anthony Bailey

    Anthony Bailey Standard User

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    Thank you Doug, I'll let you know how it all goes.
     
    Anthony Bailey, Apr 21, 2020
    #10
  11. Bill

    Bill SBIG Service and Repairs Staff Member

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    Tony,

    If you continue to have problems, email, bill@sbig.com, or call, 805 308-6979, me and maybe we can arrange the camera to come in for an inspection.

    -Bill
     
    Bill, Apr 21, 2020
    #11
  12. Anthony Bailey

    Anthony Bailey Standard User

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    Problem solved. Doug was right on the money, the cause was light leaking through a spacer thread. I did a visual inspection of the shutter as well to rule it out
    & everything is functioning normally. So it's business as usual. Many thanks Doug & Bill, your customer support is second to none.
    Stay safe & virus free.

    Best,
    Tony
     
    Anthony Bailey, Apr 21, 2020
    #12
  13. Bill

    Bill SBIG Service and Repairs Staff Member

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    That's great news Tony. Doug is right on the money quite a bit.

    -Bill
     
    Bill, Apr 21, 2020
    #13

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