[EnglishBob]

Thanks for that information. As I have never had a camera that had the facility to calibrate for lenses, that may explain my ignorance of the procedure.

The first camera I had that was able to be calibrated was my Canon 50D, that had a screen for adjustment.

Now both my 5DIII and 7DII have the ability to have an adjustment made at both the wide end, and zoomed end of the lenses range. This is much better as a lens that needs say -7 adjustment wide open, may only need -2 when zoomed all the way in.

In both cases, the adjustment is less important when you have the lens closed down as the DoF is obviously greater.