Canon 14EX - MR - Ring-type Flash Instruction Manual page 32

C.Fn-7:If an external power source is used, the flash recycling is powered
concurrently by the internal batteries and external power source. In this
case, when the internal batteries become exhausted, shooting might not
be possible. If 1 is set, the flash recycling will be powered only by the
external power source. The internal batteries will thereby last longer. Note
that even when 1 is set, the internal batteries must still be installed to
power the flash control.
C.Fn-9:If 1 is set, you can press the shutter button halfway and press it twice to
turn on/off the focusing lamp. This is convenient when both hands are
occupied.
C.Fn-3-1 is mainly for EOS-1 series film cameras. Do not use C.Fn-3-1
with EOS DIGITAL cameras or with the EOS REBEL T2/300X. If C.Fn-3-
1 is set for such cameras, the flash control will not work properly. The
flash might not fire or it might fire only at full output.
With Type-A cameras, if C.Fn-3-1 is set, wireless autoflash shooting will
not be possible.
If C.Fn-5-1 is set, single flash tube/head firing will not be possible.
If C.Fn-9-1 is set, take care when pressing the shutter button. For
example, if you keep pressing the shutter button halfway at short
intervals to autofocus, you might inadvertently turn on/off the focusing
lamp. This can also occur with the AE lock button and depth-of-field
preview button if you press twice one of them or press one button after
another at short intervals.
With Type-B cameras, even if C.Fn-3-0 is set, E-TTL II/E-TTL autoflash will
not work.
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