When using the AF button on the back of say a D700, D3, etc etc. instead of half pressing the shutter button, does this engage the camera body motor and override the lens motor or does it still use the lens focus motor?
Just curious, couldn't find anything on line/google.
It engages focus. As a result, if the lens has a focus motor of its own, then it will use that (AFS lenses for example) but if the lens does NOT have a focus motor, then it uses the in-body motor.
There is only a slight relationship between AF button and the focus motor used. It depends entirely on the lens alone.
To add to what Avi B said, if the lens has a focus motor built in, it doesn't even HAVE a connection for the internal focus motor....and likewise if the lens DOES have a connection for the focus screw drive, then it doesn't have a built in motor....
