We covered both the mechanics and optics of focusing as well as attempted a live focusing demo with an artificial star (despite the fact we couldn't turn the room lights off!)
JOhn Davis gave a great presentation on automated focusing using FocusMax.
Also, we had some great images shared by APSIG members.
You can find a link to the meeting presentation here
Some of the focusing videos are included below.
Bahtinov Focus Mask