3. "I just installed and tried a split image screen to ensure focus was where I wanted it. Autofocus ALWAYS matched manual focus - amazingly well - so the algorithm and lens control is working as expected."
-> The focusing screen is independent from the AF system and the camera focuses correctly!
NHL, no the above isn't the case. The autofocus and manual agree, but the actual image taken isstill blurry. Hence a difference in the optical path between the sensor and the focusing mechanisms (manual and auto). The only thing common to both focus screen and AF sensors and not the CCD image sensor is the primary reflex mirror.
The first 1D NEVER gave a focused image, not even once, no matter what I did.
The second (current) 1D gave focused images for a while. Now doesn't.
Repeat: the problem is that the 1D began NOT focusing. Its been working just fine for about six months. It changedhow it works (after a trip to Canon, mind you, but that I think is just a coincidence).
The D60 has been fabulously consistent in provideing great focus.