correct front/back focus issues

[paulo]

Like many others, I have a problematic sigma that front focuses.
It shows its worst at some focus distance/focal length combinations.

The idea is to make a corrective focus adjustment before taking the picture.

I have basic programming skills. How hard can it be?

[nanomad]

Next to impossible, I'm afraid. AF microadjustment is not possible since we can't control AF outside LiveView (as the "impossible features" thread says)