Blue Iris

I feel this is a stupid question, but I've spent a few hours trying to find out what "Focus Near/Far" does in the PTZ controls of the BI Console. Is that function driven by the camera's capability (to zoom, e.g.)? Another way to ask I guess is... what does that do and what are the requirements for it to do it?

My Amcrest IP3M-943B camera specs say:
I don't know what Focus Control = Manual means and the documentation from the camera's user manual doesn't address it.

Is Focus Near/Far in BI even relevant to that camera? Any help in understanding this is appreciated.

As I understand it, it is only for optical zoom, and only for manually focusing a camera that won't do it itself. My Dahua varifocal and the Dahua ptz's focus automatically after changing the zoom level - you can then see the focus changing in/out perfect.

thanks. that leads me to think that it's driven by the camera features, and mine don't have it. I can put that to bed now.