Sigma 150-600 Sports Focus Adjustment

[medic001918]

Hey everyone. I bought a second hand Sigma 150-600 Sports. Some shots seem a bit soft. It occurred to me that the seller said they did the focus adjustment through the dock when they had it. This has me wondering if that’s some of the issue?

My understanding that adjustment through the dock is similar to the cameras fine tuning, but for individual focal lengths, so 150,300, etc.

Is my thought that it’s calibrated to the previous owners body and not mine a sound thought? I don’t want to reset the lens with the dock and start over if I’m mistaken in how it works.

Thanks!