Nikon D300 User Manual page 769

using Commander mode. By using separate channels, you
won't interfere with each other.
Note: It is important to realize that all external flashes in all
groups must be on the same channel. This involves setting up
your individual flash units to respond on a particular channel.
Figure 12-12. Channel selection
They might be in separate groups but must be on the same
channel. Each external Speedlight flash will have its own
method for selecting a Group and Channel. You'll need to
acquire Mike Hagen's book, or read the user's manual for
your flash unit.
Now, let's look at the flash units you can choose for your
Nikon D300(S).
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