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CdC and PHD2


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Normally when calibrating PHD2, i slew to my target object, then pick a guide star and calibrate on that. Not sure if that is correct or not. But, whilst watching videos about PHD2, i came across one which said calibration should be done on a star 30degrees above the celestial equator, west of the meridian. Then you move to your target and guide from there.

Is calibration easier / more successful when using a 30degree star?


Now my question is: i use CdC to control my scope. The celestial equator appears in the following screenshot. You can see the meridian too. Am I right to choose a star in the circle? Or is CdC projecting a strange map? Should my coordinates AltAz or Equatorial?




Screen Shot 2016-02-20 at 15.42.41.png

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I usually slew to the object and then compose and then calibrate PHD and guide but the newest version will just start guiding on the new chosen star after you calibrate it once as far as my experience has shown.

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I've always calibrated on a star after slewing to the target. 

I can't imagine that calibrating on a star in a potentially completely different part of the sky would be better, however I'm always willing to learn if that is supposed to be the case - do you have a link to the video where this information was provided?

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From the phd2 developers, it is recommended that you calibrate at Dec zero, east of the meridian, then slew to target...PhD will take account of your then declination and make the appropriate adjustments.

this has been my method since phd2 implementation, I do one calibration then just reload it when I want to image, I never calibrate on target or after a meridian flip.

i may renew the calibration from time to time and defiantly if I move the guide camera.


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That video relates to using the drift alignment utility in Phd2 to perform polar alignment of your mount, rather than using it for autoguiding.

The information provided by Ray is interesting though as I didn't know about that.  However, as calibration typically takes just a couple of minutes or so, I think I'll probably stick with calibration at the start of each session.

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