12. AF-Assist Beam

 

In low-light or low-contrast situations, the

 

Speedlite emits the AF-assist beam

 

automatically to assist autofocusing. The

 

AF-assist beam is compatible with the

 

AF of all EOS cameras. The AF-assist

 

beam is effective with 28mm and longer

 

lenses. Its effective range in darkness is

 

indicated in the table below. See page

 

123 for details on when the AF-assist

 

beam is emitted.

Position

Effective Range

Center

Approx. 0.6 - 10 m / 2 - 33 ft.

Periphery

Approx. 0.6 - 5 m / 2 - 16.4 ft.

Automatic Reversion to Default Settings

When Speedlite 550EX is attached to an

EOS camera equipped with a < >

button, pressing the < > button resets the Speedlite’s settings (except the Custom Functions) to its default settings

As a Normal

E-TTL autoflash*

(All related settings are canceled.)

Speedlite

 

Auto zoom

 

 

 

 

E-TTL autoflash*

As a

(All related settings are canceled.)

Wireless

 

Master

 

Master flash ON

Unit

 

 

No flash ratio setting

 

 

*With the EOS-1N and EOS-1, TTL autoflash takes effect.

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Image 22
Canon 550EX manual AF-Assist Beam, Automatic Reversion to Default Settings