but rather the measure of how tight it guides.
Very true Orly. If iOptron ever puts their excellent Two Star align routine back into the HC firmware, I could post a raw PE curve.
That routine reports Polar Offset, and allows you to dial out the offset to '00-00' by using the az and lat adjusters.
iOptron replaced that routine with a 'Bright Star' type routine for users that don't have a view of the pole stars (or couldn't figure out how to use the polar offset?) at the expense of users that can see the pole stars. The new routine is not even close to being accurate enough to dial out polar offset.
I have no easy way to drift align to get to that reference point, since I have no views to the West, and my view to the East has 5 streetlamps between me and the horizon, which makes selecting a suitable star frustrating, if not hopeless..
If I had to estimate, with my tightened mount, the resident PE is probably under 5 arc-seconds peak to peak.
But, this result is off a tripod, with just a basic polar align and a One Star go-to, and guided, which is how most of the users of this mount will be using it, so it's still relevant?
And it certainly does show how well it tracks when guided.