large alignment error with polemaster & mach2


Andrea Lucchetti
 

Hello,
I need to polar align my Mach 2 very quickly to save time on field.
I thought Polemaster would have been a good choice but I cant get a good alignment with it (I am ways off)
The procedure goes very well, till the end, including the precise alignment step, but I have drift in my images.
running the Polemaster twice results in a small change.


I am not using the refraction calculation , as I leave at 42 deg latitude: can this be one of the reason?

my aim is to shoot 10 min subs unguided (@790mm focal and 1,6 arcsec/pixel resolution).

I still don't have my OTA ready so it is difficult for me to check with the drift method for the time being ( I can borrow a dslr and C8)

Would the RAPAS be a better solution for my needs? 
I understand it can be mounted on the MACH2 using a dovetail, with repeatable accuracy.
Is the accuracy enough for imaging and how it compares to Polemaster?

Thank you,
Andrea

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