Af-Assist Beam; Automatic Reversion To Default Settings - Canon SPEEDLIGHT 550EX Instructions Manual

12. AF-Assist Beam

Position
Center
Periphery

Automatic Reversion to Default Settings

22
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.
Effective Range
Approx. 0.6 - 10 m / 2 - 33 ft.
Approx. 0.6 - 5 m / 2 - 16.4 ft.
When Speedlite 550EX is attached to an
EOS camera equipped with a <
button, pressing the <
resets the Speedlite's settings (except
the Custom Functions) to its default
settings
As a Normal
(All related settings are canceled.)
Speedlite
(All related settings are canceled.)
As a
Wireless
Master
Unit
* With the EOS-1N and EOS-1, TTL autoflash takes
effect.
> button
E-TTL autoflash*
Auto zoom
E-TTL autoflash*
Master flash ON
No flash ratio setting
>