Canon SPEEDLIGHT 550EX Instructions Manual page 28

Using Flash in Other Camera Modes
G Balanced Flash Exposures
In low-light situations, the exposure level can be balanced between the
subject and background by using a slow sync speed. You can obtain
balanced flash exposures automatically by setting the camera's picture-taking
mode to Av. The camera then sets the sync speed automatically to suit the
background. Using a tripod is recommended to prevent camera shake.
Balanced flash exposure.
• To disable automatic balanced flash exposures, set the camera's picture-taking mode
to M. You can then set the desired shutter speed and aperture manually. See page
30.
Based on the shutter speed and aperture you set, the E-TTL autoflash system
controls the flash exposure automatically.
• If you are using the Canon EF 135mm f/2.8 soft focus lens on your camera without a
tripod, setting the shutter speed and aperture manually is most effective for obtaining
soft-focus effects. Follow the procedure below.
1) Set an aperture near the maximum aperture.
2) Set the minimum shutter speed required to prevent camera shake.
3) Check that the flash has recharged, then take the picture.
• To obtain balanced flash exposures in the Tv mode, set the shutter speed until the
meter reading indicates a correct exposure.
• To obtain balanced flash exposures in the M mode, set the shutter speed and
aperture until the meter reading indicates a correct exposure.
• Under flourescent lighting, the photo may have a greenish cast. And under tungsten
lighting, the photo may have an orange cast.
28
Flash exposure in the Full Auto mode.