Flexure or seeing?

[gonzostar]

A unbelievable week last week managed to guide 4-5 mins subs with my set up with phd2. Best i have ever done

Could have guided each frame for longer but the blue in the histogram was going more than half way to the right! The RMS  values for the nights varied between 0.8-1.5" Managed to get 2.5 hrs of data for M109 (over 2 nights) Which was more or less overhead heading west. 

However this weekend struggled with M57. Set up the same, same procedure balance as per normal and same procedure for for PA . RA axis ket falling off. Dec was fine. Could this also be due to flexure? How can you tell if its flexure

Seeing not so good high thin  cloud.  How much influence does atmospheric seeing effect phd2. Tried adjusting the parameters and gave up after a hour as more clouds rolled in! 

Also do  people find it easier to guide low in east or is west best?

 

clear skies 

Dean

 

 

[Davey-T]

Could be flexure as this is less apparent when aiming straight up, M109 being some 20 degrees higher than M57.

Don't know about low in east or west as I've only got an east view 

Dave

[gonzostar]

Cheers Dave. Hopefully will be clear soon with full moon, and sort those cables out. Only got ST-4 cable and cable from guide camera to laptop. Oh and DSLR cable. Hopefully this is the issue, Should be straight forward to sort out? Otherwise i am aiming high