Wireless E-Ttl Autoflash; Wireless E-Ttl Autoflash With Flash Ratio Off - Canon SPEEDLIGHT 550EX Instructions Manual

[2] Wireless E-TTL Autoflash

Wireless E-TTL autoflash with multiple Speedlite 550EXs can be used in one
of two ways:
(1) OFF : All slave units fire at the same flash output.
(2) ON
• A flash ratio can be set only with the EOS-1D, 1V, 3, D60, D30, ELAN 7/7E, and 30/33.
• With the EOS ELAN II/ELAN IIE, 50/50E, 300/REBEL 2000, 500N/REBEL G, 3000N/66/REBEL
XSN, IX, and IX 7/IX Lite, a flash ratio cannot be set with the master unit.

1. Wireless E-TTL Autoflash With Flash Ratio OFF

If no flash ratio is desired, the slave ID does not matter. It can be A, B, or C.
All the slave units will fire at the same flash output. The E-TTL autoflash
system controls the total flash amount automatically to obtain a correct flash
exposure.
G Master Flash ON + Slave Unit(s)
For indoors
For outdoors
60
: Slave units with different slave IDs (A, B, or C) can be
fired at different flash outputs to produce a flash ratio.
15 m / 49.2 ft
10 m / 32.8 ft
8 m / 26.2 ft
80°
12 m / 39.4 ft