>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.

--
RL

Visit my Nikonians gallery and my Flickr page.