I endorse venhae’s method, which I use as well.
Set up a sequence with a set of good focus targets that span the night, then rotate through all your filters and do autofocus events all night long. I can take a couple hundred of these in one night. It’s best if temperature also drops steadily through the night.
All the focus positions and temperatures are saved in the FITs headers.
I’ve written a program in R that sucks the temp and focus positions out of the FITs headers and runs linear regressions for each filter.
The slopes of the lines are all the same, indicating the temperature compensation coefficient.
The different y-intercepts of each filter’s line give the filter offsets.
In my opinion, this is a much more robust way to get reliable temp coefficients and filter offsets than any manual procedure.
It would be wonderful to build such a simple statistical analysis into SGPro. I’d be more than happy to share my R program.