The best way to test for Front or Back focus is to pick a flat object, fill it up the whole frame then shoot. It's almost like a newspaper shot.
Today I just do a newspaper shot (not exactly newspaper) for the 1st time. And I found out that my K20D has front focus issue with all of my lenses. Usually, I do manual focus so I didn't notice this problem. I proceed to do the AF adjust on the camera for each lens. Magically, I just need to dial -10 and all of them were fixed.
These are the sample shots before and after on my FA* 85
Test Subject:
Quick Eye-Ball Manual Focus:
Autofocus before Adjustment:
Autofocus after Adjustment:
I have a few more lenses to go, but so far so good. The DA* zoom is fixed for all focals.
Edit: The DA 12-24 turns out to have Back-Focus instead. So I dial +5 and things work just fine.