Hi Folks

I have just bought Panoramic Tripod Head NN Ultimate M1-S wRD16, But I could not calibrate it for my camera, I have a Canon 5D Mark2 with Sigma 15mm Fisheye lens,

So guys, if anyone has this type Panoramic Tripod Head, could you give me calibrating setting for me, I try to define dimensions like A-B-C (you can see below), So which dimensionsI have to use for A, B and C ?