Nikon D300 Complete Manual page 628

Commander:
All flashes:
Believe it or not, it's a lot more complex than that
simplification. All the Flash Options, like Rear Sync, still
come into play, which means that the Commander has to do
a lot more instructing than just ask for a preflash and a TTL
fire level.
Incredibly, all this communicating happens very quickly.
Normally, from the first preflash to the opening of the shutter
is about 60ms. If you're not watching specifically for it, you
can't see the sequence of communication. On the other hand,
you will almost surely note that there is more lag in the
shutter release and that the preflash sequence seems longer. It
is, and that can trigger fast blinkers
Since the actual communicating is done via the near IR
energy in the light each flash produces, there are limitations
on both the distance and the environment where wireless
flash will work. Outdoors has more ambient near IR and
fewer reflections, so distance is usually restricted and there
usually has to be direct line-of-sight between camera and
remote flash units. Because of bounces off walls and ceilings,
wireless flash is a bit more flexible indoors—you sometimes
can hide a remote flash out of line-of-site of the camera
because its light reflects well enough for the camera to still
see.
The jargon starts to get a little confusing, as Nikon uses
different names at different places in its documentation. For
example, Commander mode and Master flash get a little
confusing if you read multiple Nikon manuals. I'll try to stay a
little more consistent.
149 The solution for that is the same as I'll outline a little later in this section for SU-4
type wireless: use FV Lock. FV Lock removes the preflash sequence from the shutter
release, moving it instead to the Fn button. Thus, you set flash exposure by pressing
Fn. Then you wait to press the shutter release for the right moment of action (or
inaction, depending upon your subject ;~). You only have to press Fn and do another
preflash sequence if lighting conditions change.
Thom Hogan's Complete Guide to the Nikon D300
Fire!
All flashes fire at calculated levels
149
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