Canon 550EX manual Using Flash in Other Camera Modes, Camera Mode Shutter Speed Flash Aperture

2. Using Flash in Other Camera Modes

Flash photography is also automatic in the other picture-taking modes. In the Av (aperture-priority AE), Tv (shutter speed-priority AE), and M modes, the E-TTL autoflash system sets the flash exposure automatically. The camera sets the necessary shutter speed (in the Av mode), aperture (in the Tv mode), or flash output (in the M mode). Flash photography is as easy as normal AE picture-taking.

Shutter Speed and Aperture Settings for Picture-Taking Modes

Camera Mode	Shutter Speed	Flash Aperture
Av	Automatically set (30 sec. - 1/X sec.)	Manually set
Tv	Manually set (30 sec. - 1/X sec.)	Automatically set
M	Manually set (bulb, 30 sec. - 1/X sec.)	Manually set

•Manually set: You set it yourself.

•Automatically set: Set automatically by the camera.

•1/X sec.: Maximum sync speed. (see page 124)

•When the shutter button is pressed completely, a preflash fires to obtain an evaluative flash meter reading for setting the optimum output of the main flash.

•The background’s exposure is set with the shutter speed and aperture combination.

•If the camera is set to the mode (Full Auto), the shutter speed and aperture will be set in the same way as in the P mode (Program AE).

•If the DEP mode (depth-of-field AE) is used with the 550EX, it will be the same as using the P mode (Program AE).

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