Flash Shooting in Each Camera Mode
With the flash mode set to E-TTL II/E-TTL autoflash, just set the
camera's shooting mode to <s> (Shutter priority AE), <f>
(Aperture priority AE), or <a> (Manual exposure) and you can use
E-TTL II/E-TTL autoflash.
On EOS digital cameras without the [Flash control] menu function or
EOS film cameras, E-TTL II/E-TTL autoflash is set automatically.
s: Shutter Priority AE
If the aperture display blinks, it means that the background exposure will be
underexposed or overexposed. Adjust the shutter speed until the aperture
display stops blinking.
Select this mode when you want to set
the shutter speed manually.
The camera will then automatically set
the aperture matching the shutter speed
to obtain a standard exposure.
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