Hello Bob,

a simple question on pointing error,

in my script I want to image this
(J2000) RA 05:41:15 DEC -02:13:14

which is very accurate if I just just ACP point to and image. However, once I use #AUTOFOCUS, and now I am using Focusmax V4, I found there is some pointing issue,

This is the Focusmax log, per Focusmax I have excessive pointing error, but I have a 700 point T Point model which is quite accurate,

01:09:11 Plate(J2000) RA : 05:40:46.4 Dec: -02:10:27.4
01:09:11 Plate(Topo) RA : 05:41:33.4 Dec: -02:10:16.7
01:09:11 Current pointing error = 3.2945 (arc-min)
01:09:11 Max pointing error = 3 (arc-min)
01:09:11 Refining telescope position (1 of 3)
01:09:11 RA : 05:41:14.6 Dec: -02:14:54.0 (Topo)
01:09:20 Binning: 2
01:09:20 Taking 5 sec pointing exposure
01:09:29 960 catalog stars found
01:09:29 398 plate image stars found
01:09:31 ** Plate solved **
01:09:31 Roll angle= -89.98 Plate scale = 1.95V 1.95H
01:09:31 Alt= 48.4 Az= 223.92
01:09:31 Plate(J2000) RA : 05:40:37.2 Dec: -02:12:42.0
01:09:31 Plate(Topo) RA : 05:41:24.1 Dec: -02:12:31.1
01:09:31 Current pointing error = 0.0740 (arc-min)
01:09:31 Max pointing error = 3 (arc-min)
01:09:31 AcquireStar completed

anyway, after Focusmax refined the telescope position and reported good, my image finished the ACP reported excessive pointing error, which is indeed that much error in the actual image, this is the ACP log,

(exposure complete and image downloaded)
Image finished
Plate-solve final image
3077 image stars found
914 catalog stars found
Solved! 207 stars matched.
Average residual is 0.33 arcsec.
Pointing error is 9.480 arcmin @ angle 272.84
True focal length is 1896.4 mm.
True binned plate scales (arcsec/pix): H = 0.98 V = 0.98
True image center (J2000): 05h 40m 37.1s -02 12' 45.81"
Imager sky position angle is 270.0 deg.
Image FWHM is 4.9 arcsec (5.01 pixels)
(stopping the autoguider)
[flip check: Tn=0s HAc=7038s GW=T HAz=7037s DWz=T WF=no]
Re-slew to target.
Start slew to Horsehead...
(wait for slew to complete)
(slew complete)
Excessive pointing error, request pointing update for next target
[flip check: Tn=-300s HAc=7042s GW=T HAz=7040s DWz=T WF=no]
(long exp(s) or requested, no orbital tracking, trying to autoguide)


Not sure which area I missed and how to fix it? Thanks a lot.

Savio Fong