>In the zip file you will see a couple of series of 3 shots >where the target (mailbox) is centered in each of the three >images. What I did there is shoot left-sensor focus, lock and > re-center, center sensor; then right sensor focus, lock and >recenter. This was done to give me three shots with the >target centered. For good measure I simply shot left, center >and right sensor images of the same target. > >I would be grateful your insights. Do I really have a focus >problem or am I imagining this?
I haven't looked at your images, however I can tell you now that any comparison of a focused and recomposed image with one shot via the center sensor is invalid.
You can't focus and recompose to do any focus point to focus point comparison.