I don't do much video, so excuse me for asking something that's probably entirely obvious.

My wife went ice skating tonight and I experimented a bit with shooting video on the D7000.

First off all, AF jumped all over the place. Is it possible to do the equivalent of selecting an AF point and using the AF-ON button? Whenever someone moved in front of my wife AF would shift. Even with an unobstructed view it seemed unable to decide which face to focus on and just bounced all over the place. Eventually I disabled AF and shot manually. I wish I could keep an AF point on the subject and let go of the AF-ON when something gets between me and the subject... just like when shooting stills!

The horizon level is awesome.

The second is exposure. It seems to positively insist on auto ISO; doesn't matter what I set the camera to. It did seem to pay attention to aperture, but it couldn't be changed while capturing. I tried to set it to 1/15 or 1/8 for some blur effect, but it all looked the same. I think it shoots 1/60 or 1/30 no matter what. I had it set to 1080p24. I felt it underexposed a little bit, maybe 1/2 or 1/3 stop and I couldn't find any way to adjust exposure.

Quality is pretty good. It DOES seem to pay attention to the WB setting (thankfully).

Shooting video of a skating rink full of people with a fisheye is pretty wild...

Sound wasn't great, but it was actually MUCH better than I had expected!

Is there some way of controlling exposure and AF?