Guiding with Phd 2 and Mesu 200

[AstroBruiser]

Hi everyone,

 

I am curios to know wether my guiding is satisfactory as i am fairly new to all this i have wrestled with phd2 to the point where some nights my guiding is perfect to other nights where the target is hopping around and i can't put my finger on what the problem is.  I use a Polemaster for PA and my images seem to be hit and miss when aiming for 30 min subs and i have a feeling it could be better . I have attached two of my guide graphs and a  30 min fits file of NGC 3372 taken last night. I would like to hear from the experts your thoughts and if i can change anything in phd2 to get more out of my mount. I am running a 1st gen lodestar on a Moravian 16200 OAG  riding on a FSQ 106 ED.

George

ngc 3372 ha30.fit

[Guest Tuomo]

Im no expert, not AT ALL, but total RMS might indicate generally good guiding, and yours is VERY good. Secondly, correct if Im wrong, but RA-axis shows sawtooth pattern = might be because of too aggressive RA guiding.....decrease RA agr and increase hysteresis....

[Owmuchonomy]

I'm no expert either but there is an awful lot of DEC corrections in there.  If I saw that many I would be suspicious of poor PA. They are all in one direction too so switch on 'Trendlines' and see which way your drift is, N or S.  Then either improve your PA or correct DEC in one direction only (not AUTO) to correct for the drift. I don't get that many DEC corrections, ever.

[AstroBruiser]

Fortunately it is a clear night here ,unfortunately still not having much luck . I checked my PA 4 times with the polemaster and then calibrated in phd. According to phd i don't have much orthogonal error not that  it make a difference. The star i selected for my calibration was up near the celestial equator and close to the meridian. What i don't understand is some nights after a calibration it guides flawless hitting the target consistently but those nights are few and far between. No time for imaging tonight, too busy trying to figure out this guide graph and make sense of it. Here is tonights outcome