thanks for your response ,
My mount is on concrete and it is not so windy
At first i suspect the cats running into the tripod but one night i kept them inside house , same thing
I think you are right and during the night the differents slew must move a little bit the tripod . it is so sensible when i making polar alignement
i m going to slew slower may be it will help
As i m struggling with autoguiding calibration , i m looking to check every aspect. i know my mount is not very well tuned and on low end for astrophotography
an other thing, when i m doing polar aligment with ekos i m using my main scope/cam , 600mm.
yesterday at the beginning of imaging i was around 20sec arc polar error
at the end , i was around 5minutes.
I check the polar error using my guide scope , 162mm/ZWO120mm mini , and the error was around 1,5min
Why ekos mesure different polar error when using different focal lenght ?
is doing polar alignement with 600mm is not a good idea ?