STXL-16200 and FW8G-STXL FOVi

Discussion in 'STX and STXL Series Cameras' started by Sreilly, Jan 19, 2018.

  1. Sreilly

    Sreilly Cyanogen Customer

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    So I have no idea how to do this in TheSkyX and was hoping for some guidance. Getting the main chip is easy but adding the FW guide chip is not intuitive. Using this on a 16" f/8 RC I doubt there will be enough stars to plate solve. Looking for any positive thoughts please.

    Thanks,

    Steve
     
  2. Doug

    Doug Staff Member

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    Yes that is somewhat difficult, due to a combination of the adjustable offset and the focal reducer optics.

    What I did on my setup was use the moon. I adjusted the telescope position until the limb of the moon was on the guider. Then I adjusted it until it was at the edge of the main CCD. The difference in declination (or right ascension times 15 to get arc-minutes) is the distance between the chips.
     
  3. Colin Haig

    Colin Haig Staff Member

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    Steve, I've heard some folks will use Pinpoint to plate solve both the guider image and the main image, but you have to be in an area with quite a number of bright stars. Not sure it would work... just heard somebody did it.
    Doug's idea sounds pretty good to me. Esp if its a nice crescent like tonight.
     
  4. Sreilly

    Sreilly Cyanogen Customer

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    Not sure if this is a good question as I'm trying to help a friend but does the filter wheel only attach in one orientation on the camera? Is there a way to know exactly how the guide mirror is rotated to the main chip? Some rough starting point would be good and then nudge the mount slightly until you have your target star on the mirror and then try to compute the distance from the imager chip's center. Or is this not going to work.
     
  5. Doug

    Doug Staff Member

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    The recommended orientation places the cables on the filter wheel on the same side as the connector panel on the camera. It is possible though to mount it in different orientations.

    The trick I used in my observatory was to target the moon. It's very easy to find! If you're off target then you can see the sky background gradient and know which way to move.
     
  6. Sreilly

    Sreilly Cyanogen Customer

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    So if the camera is mounted as suggested, in which direction is the guide chip when facing the back of the camera mounted on the telescope? Up/Down/Right/Left? It should be one of those correct? Then it's a matter of determining the offset from center of the imaging chip?

    Thanks,

    Steve
     
  7. Doug

    Doug Staff Member

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    I don't have the answer handy. And there is the risk of confusion since things are inverted in a telescope, there's a mirror on the guider, the software can be set to invert the image, etc. I found using the moon very quickly clarified the situation.
     
  8. w4sm

    w4sm Cyanogen Customer

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    Doug, I'm the guy Sreilly has been helping. I have an STXL 16200 with FW8G-STXL filter wheel and off axis guider. Part of the problem, I think, is that my guide imager is very insensitive. I followed the advice on this thread:
    http://forum.diffractionlimited.com/threads/stxl-16200-and-stxl-fw8g.3259/

    My guider offset was set at "255." The Default value is "0." I set the guider to the default, but didn't mess with the main imager (offset = 131). I haven't had a chance to test this yet. My question is, in CCDOPS -> Advanced there seems to be no way to set an arbitrary value to the offset. That window is "greyed out." All you can do is restore the default. Is there a way to set an arbitrary value? I'm hoping the default fixes my problem. Thanks!
     

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