User guide

Multi-Speedlite System

Sample Wireless Flash System

You can easily set up an E-TTL wireless autoflash system with the 550EX,

ST-E2, or MR-14EX as the master unit and the 420EX as the slave unit.

Just set the 420EX's wireless selector to <SLAVE> and position the slave

unit(s) as desired within the wireless transmission range

420EX (Slave unii)

420EX (Slave unit)

Q • The 420EX and 550EX can be set and used together as wireless slave units.

• If the 420EX slave unit is not used for about 10 minutes, the SE mode (^page

14) will take effect (indicated by a blinking channel No.) automatically to turn off

the power.

Pressing the master unit's test firing button within 30 minutes after the SE

mode starts will turn the slave unit back on.