Hi Peter,
Yes, I think theoretical CFZ for my system is between 70-100 um, but in practice it seems smaller than that. I am not binning for autofocus.
I do not use offsets for filters as I feel there may be more variables involved in obtaining good focus than just temperature, so I prefer refocusing on the night when on the target and with the filter in place rather than using offsets.
I think you can also use half-steps with Moonlite ,if needed.
With half-steps you have 0.00008" of focuser movement per half step (2 microns per half step) - should be sufficient for f4 system
