yuhi, what u asked is somehow confusing.
hunt mean finding. before hunt, u have to make sure u point at something that is focus-able, something contrast-y. in AF-S and AF-A, once it lock (teet teet) it will not hunt again. the 70200G has DMF where u can turn the focus ring instantly after AF to fine tune ur focus. but not all lens has DMF, so be careful
the AF-C will continue to try to re-lock and re-lock and re-lock (without teet teet).
the aperture will not close down until u full press the shutter button.
and the DOF preview button (if u set the lens custom button to DOF preview) it will close down the aperture when u press it (u notice ur OVF gets darker too) but AF mechanism is locked out, so the camera dont really focus when the aperture close down. but on certain lens with DMF, u can fine tune focus with it.

minolta/sony alpha AF (and other brand is the same) will not AF with lens that is darker then F6.3 (lens with manual aperture) like samyang FE or 85mm. in other words, u wont get AF confirmation for lens darker then F6.3
except for a very very special case, the minolta/sony 500mm F8 mirror reflect which still works with AF even its a F8.
Added on March 4, 2011, 11:01 pmcan see ah?

dont ask, she's doing her spidey thingie....
This post has been edited by ieR: Mar 4 2011, 11:01 PM