Originally Posted by
DanK
With that additional information, I'm stumped.
From what you posted, the main difference between the two tests was shutter speed. Since the blurry image was the longer shutter speed, slow AF can't be the culprit.
It's very hard to see what's going on with such a tiny posted image (can you use a link to post to a larger one), but I do see one thing that strikes me as weird. Look at the noise in the top band of the right half in test #1. The noise is more blurred near the center. To a lesser degree, that's true further down in the image as well. Since the noise is generated by the internals of the camera--the sensor and the circuitry--that shouldn't be so, if AF is the problem. Or am I off base?