Canon 600EXII-RT Instruction Manual page 117

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C.Fn-21:
You can change the flash light distribution (flash coverage) of the Speedlite
in relation to the shooting angle of view when the flash coverage is set to
<L> (automatic).
0: j (Standard)
The optimum flash coverage for the shooting angle of view is set
automatically.
1: k (Guide number priority)
Although the periphery of the picture is slightly darker than the 0
setting, this is effective when you want to give priority to the flash
output. The flash coverage is set automatically to a slightly more
telephoto position than the actual shooting angle of view. The display
changes to < k >.
2: l (Even coverage)
Although the possible flash photography distance becomes slightly
shorter than the 0 setting, this is effective when you want to minimize
light fall off at the periphery of the picture. The flash coverage is set
automatically to a slightly wider position than the actual shooting angle
of view. The display changes to < l >.
<
C.Fn-22:
When a button or dial is operated, the LCD panel illuminates. You can
change this illumination setting.
0: 12 sec (On for 12 sec)
1: OFF (Disable panel illumination)
2: ON (Illumination always on)
?
C.Fn-23:
When the slave unit is fully charged during wireless flash photography, the
AF-assist beam emitter of the slave unit blinks. You can disable this
blinking. Set this function on each slave unit.
0: = (AF-assist beam, Q lamp)
1: > (Q lamp)
(Light distribution)
(LCD panel illumination)
(Slave flash charge check)
C: Setting Custom Functions
117