Lost Guide star after dither

Discussion in 'Image Capture' started by Up2Late, Apr 23, 2016.

  1. Up2Late

    Up2Late Cyanogen Customer

    Joined:
    Dec 25, 2015
    Messages:
    4
    Location:
    Mount Hope, ON, Canada
    Just like the title says, after the image downloads and dither the guide star is no longer in the frame.

    I got a new guide camera, ZWO ASI120MM, and have been using it. The first night that I used it everything work excellent but I haven't got it to work properly since then. I have dither set to Via Guider.

    I can't figure out what is going on. Any thoughts?

    Scott
     
    Last edited: Apr 23, 2016
  2. Up2Late

    Up2Late Cyanogen Customer

    Joined:
    Dec 25, 2015
    Messages:
    4
    Location:
    Mount Hope, ON, Canada
    I have set the guide frame size to 64 x 64 and with the guider max. dev. set to 1.50 pixels it is moving the guide star to the edge of the frame. I had noticed that my setting were incorrect for the guide camera optics as they were set for my OAG (616 mm f.l. 110 aperature) rather than my guide scope (545mm f.l. 80 aperature) and changed them accordingly but that hasn't made a difference.

    I have also changed dither to Via Mount which seems to allow me to at least take some images but I'm using the guide port for guiding. My understanding is that dither should be set to Via Guider in this case.
     
  3. Up2Late

    Up2Late Cyanogen Customer

    Joined:
    Dec 25, 2015
    Messages:
    4
    Location:
    Mount Hope, ON, Canada
    I suppose I can just use the software as I am but I don't think it's correct. I wonder if someone who might know Maxim better than I might have any suggestions?
     
  4. EricC

    EricC Cyanogen Customer

    Joined:
    Jan 31, 2015
    Messages:
    161
    Is the problem only after you dither, or all the time when guiding?
    If only after a dither, perhaps your dither distance is too large. 1.5 pixels doesn't seem like much but try lowering it to 0.5.

    If the problem occurs all the time, did you calibrate the guider so it knows which direction to move the mount? If not, or if you haven't calibrated it since you last change the camera position, guiding can give the results you are seeing.
     
  5. Doug

    Doug Staff Member

    Joined:
    Sep 25, 2014
    Messages:
    6,887
    You can't dither via mount while guiding. You have to dither via guider, otherwise the guider will either lose the guide star or guide it back to where it was in the first place.
     

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