Canon 550EX - Manual (Page 16)

5. Main Switch
The main switch has three settings as shown below.
Turns off the power.
Turns on the power.
Turns on the power and enables the SE
mode.
• The SE (Save Energy) mode turns off the
Speedlite automatically after a period of non-use
as Indicated In the following table.
Wireless Selector Setting
OFF MASTER SLAVE
90 sec 60 min
When the wireless selector Is set to Sffi) or MASTER and the SE mode takes effect, the LCD
panel display turns off. To cancel the SE mode, either press the camera’s shutter button halfway
or press the Speedllte’s test firing button The Speedlite will then turn on again.
If the wireless selector is set to SLAVE and the SE mode takes effect, SE is displayed on the
LCD panel. If the time limit (1 hour or 8 hours) for turning on the Speedlite again (SE mode
cancellation) elapses, SE turns off on the LCD panel. In this case, you must turn the Speedlite’s
main switch off and on again to turn it on again.
Custom Function CF-4 can alter the time it takes before the slave unit enters the SE
mode See page 113.
Custom Function CF-5 can alter the time limit for the master unit to be able to cancel
the slave unit’s SE mode. See page 113.
Memory feature
The Speedlite’s current mode, zoom setting, flash exposure compensation setting, etc.,
are retained in memory even after the Speedlite is turned off. When the Speedlite is
turned on again, all the settings remain effective. When replacing the batteries, the
settings stored in memory can still be retained if the new batteries are installed within one
minute.
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