[davidmanze]

Hmmm.

 

In my experience the AF-C on Nikon remains quiet when I reactivate contionous AF no matter, what's happening or if the camera's mounted on tripod or not when I turn the aperture wheel. Also, when I stop AF and refocus again, I always hear a sound - and the focus scale / ring is moving a fraction. I must say, impressive you see that - if I recall correctly, the focus scale and ring is quite dense on the Tamron: 0.29____0.5___0.7__1.1_3 ∞ (had to look that up). Hard to see movement between 3 m and âˆž.

 

Edit: As for selling your Pentax gear: It was an easy way to go for me, I never grew to the K-m and K-x. Cheap ffeling plastic stuff, I never looked back. With K-3 and K-5 I wouldn't feel so easy about, but at the other hand: Although I like some of the features of the new FF Pentax and would go for a new body with those appearing in a Nikon (the very special tilting LCD, U1...U5(!) and the wheel with some menu settings on top of it) I would not go back to Pentax anymore. Lenses are limited and I recall some manufacturers stopping to offer interesting lenses in K-mount.

   Don' forget the Tamron 17-50 is on the K3 here.......It is not necessary to read the scale to check the focus change, you can hear the screw-drive "gruck" and see a "slight" barrel movement we are talking 5cms front focus at  2.5 meters or so, just enough to ruin the shot!