The button produces key-down / key-up events
So the accumulated position changes smoothly
If. I. Turn. The. Knob. Slowly. Then. It. Works. Fine.
It can focus absurdly close to the lens
Not everyone agrees with my choice of retina-burn orange PETG
The RPi will happily stream video all day long to ffmpeg
It’s recessed below the surface and requires a definite push