External Speedlites; External Flash  - Canon EOS 7D Instruction Manual

External Speedlites

EOS-dedicated, EX-series Speedlites
Basically operates like a built-in flash for easy operation.
When an EX-series Speedlite (sold separately) 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 compatible with flash function settings

(p.119), only [Flash exp. comp] and [E-TTL II] can be set for [External
flash func. setting].
(Certain EX-series Speedlites also enable [Shutter sync.] to be set.)
If the flash metering mode is set to TTL autoflash with the Speedlite'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 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
133