Calibration doesn't do what you think it does. The name is a poor description of the actual function. It tries to auto-sense the tracking, beyond what normal tracking does.
Auto-tracking responds to errors when found.
Calibration tries to use a crystal ball, and avoid tracking errors before they occur.
Calibration = OFF = recording/playing straight line
Calibration = ON = wiggling about, trying to find "best" tracking, but in practice does poorly at it
For recording, this thing is horrible. It makes the whole tape untrackable.
For playback, it rarely works. More often than not, it cause vertical (layman) jitter, because it will hit the tracking boundary.
Don't use it unless it is shown to help, which will be less than 1% of the time.
It's somewhat useless, like R3 sharpening.