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Just a bit of an update.
Got under my deck yesterday and discovered to my horror that the bolts holding my pier down were only finger tight! Heat/cold cycles I guess?
So, spent most of last night just redoing T-Pointing and finally dervied a new model that looks pretty good. RMS=8.5 (200 points), MA= 23.5, and ME = 15 (from refracted pole). I managed to do this in two runs. The first was about 50 points that I took care to make sure included the extremes of what is visible from my location. I had never previously taken points that low down but I'm assured by Patrick Wallace that the MA term requires these for more accuracy. I then moved the mount according to the T-Point super model recommendations but I confirmed both moves photographically. Again, from Patrick Wallace I learned how to do this for MA: cos x altitude angle (on meridian pointing North) x arcsec move indicated from T-Point PA = actual move to make. Thus, if T-Point says move 1 arcmin in MA and the scope is pointing 40 degrees dec then: cos(40 degrees) x 1 arcmin = .766 arcmin (the amount you move the scope photographically). It will work anywhere in the sky but on the meridian it's easier because the declination control will move the scope in a way where it is easiest to measure the actual move (in a vertical line if camera has dec=Y).
I used my ST-i in focus mode and the jog controlls to do this.
After making the moves I ran a 200 point model and was pretty happy to see how close it ended up. For the 200 point model I started out by taking about 10 points manually again selecting the extreme points in the sky visible, but for the remainder of the 190 points I confined the run to about 35 degrees and higher.
Should I worry about the MA term, or is it close enough?
Peter
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