Canon manual Wireless System Setup and Testing, Setting the 550EX as the Master Unit

[1] Wireless System Setup and Testing

The wireless flash system can be setup in one of two ways: 1 With a 550EX set as the master unit and one or more 550EXs set as slave units. 2 With Speedlite Transmitter ST-E2 (sold separately) used as the master unit and one or more 550EXs set as slave units.

This section describes the procedure for the former. For the latter, refer to the Instructions for Speedlite Transmitter ST-E2.

1. Setting the 550EX as the Master Unit

Attach the 550EX to the camera and set

the wireless selector to . This 550EX will then be the “master unit.” The master unit’s wireless signal is transmitted to the slave unit(s) at almost the same time as the preflash.

The master unit’s flash head zoom setting is set automatically to . This gives the

wireless signal the maximum coverage of 80°. You can also press the button to change the zoom setting manually. However, this will narrow the wireless signal’s coverage.

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