Nikon D300 User Manual page 206

D
Using FV Lock with the Built-in Flash
FV lock is only available with the built-in flash when [TTL] (the default
option) is selected for Custom Setting e3 ([Flash cntrl for built-in flash],
pg. 291).
A
Using FV Lock with Optional Flash Units
FV lock is also available with SB-900, SB-800, SB-600, SB-400, and SB-R200
flash units (available separately). Set the optional flash to TTL mode (the
SB-900 and SB-800 can also be used in AA mode; see the flash manual for
details). While FV lock is in effect, flash output will automatically be
adjusted for changes in flash zoom head position.
When Commander mode is selected for Custom Setting e3 ([Flash cntrl for
built-in flash], pg. 291), FV lock can be used with remote SB-900, SB-800,
SB-600, or SB-R200 flash units if (a) any of the built-in flash, flash group A,
or flash group B is in TTL mode, or (b) a flash group is composed entirely of
SB-900 and SB-800 flash units in TTL or AA mode.
A
Metering
The metering areas for FV lock when using optional speedlight are as
follows:
Speedlight
Stand-alone flash unit
l
Used with other flash
units (Advanced
Wireless Lighting)
A
See Also
For information on using the depth-of-field preview or AE-L/AF-L button for
FV lock, see Custom Setting f5 ([Assign preview button], pg. 305) or
Custom Setting f6 ([Assign AE-L/AF-L button], pg. 306).
180
Flash mode
i-TTL
Area metered by flash exposure
AA
i-TTL
AA
Area metered by flash exposure
A (master flash)
Metered area
4-mm circle in center of frame
meter
Entire frame
meter