User guide

Main Switch
The main switch has the foiiowing settings.
OFF-
OFF-
■ON
TO
■ON
TO
Turns off the power.
Turns on the power.
After 90 sec. of non-use, the SE
(Save Energy) mode takes effect
automatically to turn off the 420EX
and save battery power.
• To cancel the SE mode, press the
test firing button.
High-Speed Sync (FP Flash) Switch
The high-speed sync switch has the foiiowing settings.
TO
TO
Vh
Sets the normal sync mode.
Sets the high-speed sync mode.
a
When the 420EX is used with a Type-A camera and the switch is set to <^>,
setting a shutter speed faster than the camera's fastest sync speed sets the
high-speed sync mode. And using a shutter speed slower than the fastest sync
speed sets the normal sync mode.
When a Type-B camera is used, the normal sync mode takes effect regardless
of this switch's setting.
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