I can back you up on that. I work on a highly custom system that uses EF lenses through an EF-to-serial adapter. The lenses don't even know what position they're at when you power them on. If you want to move them to a specific focus step you have to go through a homing procedure that drives the focus motor to a stop (I don't recall if it's the near or far stop).
Lens-to-lens it's definitely not consistent. Step 142 on two different lenses will have a different focal depth. We calibrate each lens ourselves (thankfully you can read the serial number through the EF mount) and then still have to do closed-loop image-based sharpness estimation to guarantee that things are as good as we can get.
Lens-to-lens it's definitely not consistent. Step 142 on two different lenses will have a different focal depth. We calibrate each lens ourselves (thankfully you can read the serial number through the EF mount) and then still have to do closed-loop image-based sharpness estimation to guarantee that things are as good as we can get.