Nikon D300 User Manual page 358

any flash units out there in
"commanding".
Group A or
unlimited number of remote mode (slaved) Speedlights that
your camera can control and fire under the Nikon Creative
Lighting System (CLS). Each group has four settings that
apply to each flash unit in that group
Following is a description of each setting:
▪ TTL – This works like
all flash units being controlled in each
(i-TTL) for that group. You can also set compensation
(Comp.) between +3.0 and -3.0 EV in 1/3 EV steps.
Comp. will affect all flash units in that group.
▪ AA – This stands for Auto aperture and is only available
when your D300(S) is contolling an SB-900 or SB-800
Speedlight flash unit in slave mode on a bank. This is an
older technology that does not use the newer i-TTL
exposure technology. It is included for those who are
used to using the older style of exposure. You can safely
ignore this mode and use
better exposures. If you really want to use
that's fine. It works like
accurate exposures. You can set compensation (Comp.)
between +3.0 and -3.0 EV in 1/3 EV steps. Comp. will
affect all flash units in that group.
▪ M – This allows you to choose a manual flash level
between 1/1
for each of the flash units being controlled by that
particular group setting. If you like to shoot manually for
B – These groups represent groups of an
Built-in flash
(full power) to
358
Group A or Group B
(TTL,
except that it causes
Group
TTL instead, and you'll get
TTL mode, but with less
1/128 (1/128 of full power)
that it is
AA, M, - -).
to use TTL
AA mode,