Paul & I shot a pre-wedding party last night which was in a pretty dark bar and it was a nightmare focusing. We have the infrared auto-focus assist set to on on our SB-800s but they're not working on either of our cameras. Paul was using a D3 with three different lenses & I was using a D3 with a 24-70mm. We've checked the manual which says it'll only work on certain focus points and we've set the focus to those but it still won't fire the infrared beam. Any other ideas? Could it be incompatible with the D3??? Would really appreciate any suggestions as we're shooting the wedding tonight!

Nevermind! I've found the answer - it only works in Single Servo AF. We had both the cameras set to continuous focus!

It only works in Single Servo AF, not in Continuous.....oh. You knew that already.

Not that, you know, *I've* ever made that mistake.

the placement of the autofocus selection is stupid. Somehow I always end up back on C mode.

Added note you have to be on the center focus postion also, with the kiler 52 point AF system you can think your in center and not be and no foucs light. Hit the center button and the focus point will go to center automatically.

Been there, done that! The focus button on my D200 always accidently moves for me too.

Same thing has happened to me, I've accidently moved the focus switch on my D200 many times. I now keep a closer eye on it and hope they have improved the switch for the D300.

Glad I'm not the only one that moves switches without realizing it!!