> You mention that your mount will normally correct for atmospheric refraction ...
> Do you mean for the GOTO position of the target ? or the tracking is active corrected during the observation ?
> Only professional mount with direct drive motors on both axis and a full pointing model can do that.
> Before looking the last arcseconds ... are you sure that your setup is stable at that level ?
The mount is professional quality, on a 1m diameter peir and can be set to correct (or not) for any and every parameter you can dream of...
Yes, the setup should be stable at arc-second level...
https://www.clubastromars.org/le-club/l ... %A0-access
> You can do the following test: Perform the SharpCap Polar Alignment 2 times.
> The first time with the telescope tube on the East side and then 90°, the second time with the tube on the West side and then 90°.
This is definitely something that I will try.
THANKS for the sharpcap setup dialog that I completely forgot about as I do not use if for my own scope (which is DEFINITELY NOT at arc second level https://sites.google.com/view/brebisson ... 2jp372oute
Next time I check the big scope alignment, I will definitely do a good job at checking every parameter there!
Thanks again for your help.
Cyrille