>"Only works in AF-A or AF-S." Apparently means it >>is set to AF-C. > >But AF-A switches between AF-C and AF-S, doesn't it? Or am I >getting trapped in the Nikon's terminology/ Is it the case -- >that AF assist with the SB-600 mounted on the hot shoe -- >works when I set the camera to AF-A AND the camera then sets >itself to AF-C (or, in other words, acts AS IF it were in >AF-C)? What is going on?
AF-A always starts out in AF-S mode. So when the AF-Assist light comes on, you're in AF-S. On my D90, when my SB-600 is mounted, AF-A never switches into AF-C mode. It's as if it's disabled. This behavior is undocumented. So you need to check your D7000 to see if AF-A even switches to AF-C when the flash is on the camera.
When the SB-600 is not mounted, the built-in AF-Assist light comes on for AF-A initially, but remains off when the camera switches to AF-C.