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Flash Photography
4
Flash Photography with the EOS-Dedicated 550EX Speedlite

FE Lock

The procedure for setting FE lock is the same as with the built-in flash (90). FE lock works in
both the normal flash and high-speed sync (FP flash) modes.

Flash Exposure Compensation

For flash pictures with flash exposure compensation, see Flash Exposure Compensation for
the built-in flash. (91)

Modeling Flash

Modeling flash allows you to see shadows, light balance, and other effects produced by multi-
light settings.
1Check that the camera and
Speedlite are properly set for flash
photography.
2Press the camera’s depth-of-field
preview button.
The Speedlite fires at 70Hz for approxi-
mately one second.

Wireless Multi-Flash/E-TTL Autoflash Shooting

The 550EX Speedlite can be operated as a slave light from a master (550EX or ST-E2) for
easy wireless multi-flash/E-TTL autoflash photography. The slave 550EX is placed to supple-
ment the master flash, which provides the primary flash for the subject.
This is a Type-A camera. For details, refer to the instractions for your master Speedlite.
Macro Ring Lite MR-14EX and Macro Twin Lite MT-24EX can also be used as the
master unit, and Speedlite 420EX can also be used as a slave unit.