Canon 550EX manual Main Switch, Memory feature

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 or 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 Speedlite’s test firing button. The Speedlite will then turn on again.

•If the wireless selector is set to 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.

CF

CF

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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