[g__day (Matthew)]

Wondering what does settling indicate - especially when guiding is normally pretty close to perfect each night - and I have told both imaging scopes camera guide control (SGP and APT) not to dither.

What is going on if its not clouds or cable snags etc?

My gear is in a back yard astro lab - remote controlled from within the house. Three Williams Optics refractors on Losmandy rails attached to an old Vixen Atlux controlled by a Skysensor2000-PC (set to polar aligned mode, with PEC and target based refraction compensation active - if that matters) on a large pier attached to a very large block of concrete under the lab.

Regarding polar alignment - The SkyX and Tpoint says is pretty much perfect - about a tenth of an arc second under the refracted South Celestial Pole - guiding three moderately heavy scopes, focusers, filter wheels and cameras is routinely great - corrections about +/- .025 arc second and trivial drift per minute to correct out. So its only this settling that has me puzzled.

Next session I might observe guiding with APT or SGP inactive to see if one of both of them are actually issuing dither commands when I have tried very hard to tell them not too!

Many thanks, Matthew