ST-i Guider Settings

Discussion in 'Specialty Cameras SG-4, AllSky, ST-I' started by Brian O'Rourke, Jan 22, 2015.

  1. Brian O'Rourke

    Brian O'Rourke Cyanogen Customer

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    I'm using the Colour ST-I Guider/Kit (100mm f2.8). My scope is a Tele Vue NP 101 (540mm f5.4) with a Canon 60Da for imaging (pixel size 4.3 image scale 1.6 asp).
    What would the best settings be in your auto-guider setup?

    Thanks Brian
     
  2. Tim Puckett

    Tim Puckett Guest

    Brian,

    What software are you using to guide? What mount you using
     
  3. Brian O'Rourke

    Brian O'Rourke Cyanogen Customer

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    Hi Tim;
    I'm using a Losmandy G-11 with Gemini 1.4. The software is PHD2 with BackyardEOS. I haven't had much luck with PHD, but it integrates with BackyardEOS. I had better results with CCDOps, perhaps because there are fewer things to adjust.
    If you could give me SBIG's recommended settings for PHD2 that would be great.
    I tried MaxIm DL's autoguider, but was overwhelmed with the settings on it as well. I plan on purchasing MaxIm in the near future, so if its not a burden perhaps you could recommend the best settings with it as well.
    Thanks very much for the speedy reply;
    Brian
     
  4. Tim Puckett

    Tim Puckett Guest

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  5. Brian O'Rourke

    Brian O'Rourke Cyanogen Customer

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    Thanks Tim;
    I found a posting on the Google/PHD site that gives me something to go on.
    What would you recommend on MaxIm/Advanced Tab, for the minimum move, it's in fractions of a second where PHD is in pixels?
    Thanks Brian
     
  6. Tim Puckett

    Tim Puckett Guest

    Brian,

    I would try the default at 0.01
    Below is from the manual.
    Use the calibrate command and adjust the settings until you get a good calibration.

    Regards
    Tim


    The Guiding controls set limits for track mode operations. The Minimum Move X and Minimum Move Y sets the smallest motion the autoguider will make. This provides a small ”dead band” which can be useful for preventing oscillations in the guide star position due to unnecessary corrections, and to help overcome the effects of backlash. The Maximum Move X and Maximum Move Y can be used to limit the maximum amount of motion permitted during guiding. Lowering this value can prevent the guider from tracking out a momentary large error, such as might occur if a large wind gust occurs.

    A non-zero value in the Delay After Correction field causes a time delay after each guider output command. This allows time for the telescope to settle (or, in the case of serial output command mode, for the guider activation itself to complete) prior to taking the next guider image. A small delay is also recommended when using Losmandy mounts.

    The Move Commands settings control the behavior of the Move dialog (accessed using the Guide Tab’s Move button). Maximum Slew X and Maximum Slew Y limit the maximum slew that will be performed using this command. These limits can be set to prevent large, accidental slews. The Delay After Command control allows you to program in a delay after each move command. It should be used in the same situations for which Delay After Correction is recommended.

    The Guider Motor Control affects how commands are sent to the mount, as follows.

    Some telescope mounts can accept guider move commands for both axes simultaneously, but some cannot. By default, MaxIm DL sends correction commands to each axis sequentially. If your mount is capable of guiding in both axes at the same time, you can turn on Enable Simultaneous RA and Dec Correction. Doing so will speed up the guider cycle time slightly; however, if your mount cannot accept simultaneous commands it may act very erratically and fail to guide. If in doubt leave this setting turned off. Also, this setting is ignored when Control Via is set to Telescope because the ASCOM telescope interface does not permit this mode of operation.

    Following a pier flip, most mounts will reverse the direction of autoguider commands in the Y direction. This is actually the result of the camera rotating 180 degrees (reversing both X and Y), and the direction of mechanical declination reversing (reverting Y back to normal). By setting On Pier Flip Reverse X, the autoguider calibration will automatically be preserved after a pier flip. This setting works for most telescopes, as long as X is wired to RA. If X is wired to Declination, then select Reverse Y. Some mounts behave differently due to intelligence in their controller, and preserve the sense of the declination axis. For these mounts select Reverse X and Y. A Do Not Change option is also provided, which will do nothing when a pier flip occurs. Some mounts do not report "side of pier", in which case MaxIm DL has to "guess" what side they are on. Some of these mounts, including the Paramount ME, can be difficult to predict. The Adaptive mode watches the guide star, and if it starts to drift away it automatically reverses the guide corrections. The Adaptive mode will often take longer to settle after a pier flip or slew, but guiding should not fail completely even if the telescope does something unexpected. Please note that these settings require Auto Pier Flip on the Guide tab to be turned on in order to have any effect. Also please note that you may need to recalibrate the guider after changing this setting.
     
  7. Bob Denny

    Bob Denny Cyanogen Customer

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    Be aware that the Gemini has frustrated many people. Patience and trial-error will eventually pay off. The Gemini group on Yahoo can be of help.
     
  8. Brian O'Rourke

    Brian O'Rourke Cyanogen Customer

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    Hi Bob;
    Thanks I'll check that out. I'm beginning to suspect the Gemini....I've been getting non-responses and lock ups with MaxIm and Gemini using the pulse-guide but its fine using CCDOps and guide relays.
    Brian
     
  9. Bob Denny

    Bob Denny Cyanogen Customer

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    It should be fine with guide relays with MaxIm then. Try that :)
     
  10. Brian O'Rourke

    Brian O'Rourke Cyanogen Customer

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    I did try that and it worked really well! Perhaps unrelated, but I sandwiched my USB hub between two Jim Kendrick Dew Heaters and it everything worked even though it was -10C . Next clear night I'll try going back to pulse-guide and see if the hub was the problem.
    Thanks for your help, Brian
     

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