Re: [APML] STV dumb question

["Mike Cook, AF9Y" <mwcook@concentric.net>]

> From:           	Tonyhallas@aol.com
>
> Mike,
> 
>     I understand your idea about turning off the guiding while in the graph mode... how???
> 
       Select the manual mode for guiding (where you can set the X and Y aggressiveness).
       Then just set X and Y to 0.   You can then see long term mount tracking error
       as well as the scintillation.   The Monitor Drive modes can also show
       scintillation but you don't have control of the update period.

>     I have the "CRT" version... so what I am seeing is only the scintillation of the star
>     on the graph... not the guiding?

       You are seeing the combined result of scintillation and guiding.

>     But I do notice that the image of the star in the box
>     is a real indication of the guiding... at 1.0 it moves around quite a bit if the
>     seeing is bumpy, at 0.2 it seems to calm down a lot, typically moving 1/2 star
>     diameter.

       Yes, a 1.0 aggressive setting with 1 sec guiding rate will directly follow
       the fast scintillation rather than the slow mount error.  I typically use
       between 0.2 and 0.6 with a fine tuning adjustment after watching the
       graph.  You can typically tell when the setting is too high because the
       errors become less random with small to large oscillations of
       over corrections.   I typically use either 1 or 1.5 seconds for the
       guiding period.

        One other note.  If you have any backlash in the system, it is best
        to calibrate with the mount backlash compensation ON.  Then reduce
        the compensation to 1/2 of the value used during the calibration.  Of
        course, your mount probably does not have this added variable to
        deal with.   


 My most recent shots last night gave me refractor-like stars... not bad for
>     3000mm focal length!

      Excellent!  



Mike Cook, AF9Y
http://www.webcom.com/af9y
mwcook@cris.com




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