Guiding v2

After many months of waiting I finally have some new gear (more later).  I’m back to problems with guiding.  PHD worked perfectly on the Tak FS 102 NSV with my SBIG ST402ME (9 micron pixels) and my Planewave Ascension 200 HR mount.  The the focal reducer I was running gave me an arcsec/pixel ratio of about 3.  Deviation from zero was max 0.4 pixels on a bad seeing night.

Enter the new gear – OfficinaStellare 400mm F 3.8 RILA.  Focal length is 1520mm.  The guidescope now sits on a MMOAG with my Proline.  The guiding was lousy!  More like averaging 3 pixels variation.  Now the stars in the guider where not very round – they where lousy not even oval.  First step adjust the angle of the prism/mirror on the MMOAG. One small piece of folded over tape later (under the back edge of the blocks that hold the prism) and my stars now look like ovals.  Tracking improved a lot.  Average deviation from the mean is < 0.5.  Now I use PHD 2.0 because it’s easy and I’m dumb.  Alas it does not seem to support binning – come on Craig.  The SBIG on this rig has an arcsex/pixel ration of 1.22 – not good in Sydney sky’s.  So I went back to Maxim DL for guiding and binned 2×2 (arcsex/pxiel now surprisingly 2.44).  My guiding even with all the high cloud last night was great – deviation from average max 0.2 pixels.  Yeah!

Training the scope for guiding in Maxim is still a pain – some times it misses the star altogether, sometimes the stars become stripes etc BUT regardless it guides really well.