External Speedlites; External Flash - Canon EOS 50D Instruction Manual

External Speedlites

EOS-dedicated, EX-series Speedlites
Basically operates like a built-in flash for easy operation.
When an EX-series Speedlite is attached to the camera, almost all the
autoflash control is done by the camera. In other words, it is like a high-
output flash attached externally in place of the built-in flash.
For detailed instructions, see the EX-series Speedlite's instruction
manual. This camera is a Type-A camera that can use all the features of
EX-series Speedlites.
Shoe-mount Speedlites
With an EX-series Speedlite not controllable by the camera, only [Flash
exp. comp] and [E-TTL II] can be settable for [External flash func.
setting] (p.111).
(For some EX-series Speedlites, [Shutter sync.] can also be settable.)
When the flash metering mode is set to TTL autoflash with the flash's
Custom Function, the flash will fire at full output only.
Canon Speedlites other than the EX-series
With an EZ/E/EG/ML/TL-series Speedlite set in the TTL or A-TTL
autoflash mode, the flash can be fired at full output only. Set the
camera's shooting mode to <a> (manual exposure) or <f>
(aperture-priority AE) and adjust the aperture setting before
shooting.
When using a Speedlite which has manual flash mode, shoot in the
manual flash mode.
Macro Lites
113