Canon EOS REBEL T5 Instruction Manual page 196

3 Setting the FlashN
Flash mode
When using an external Speedlite, you can select the flash mode to
suit your desired flash shooting.
Shutter synchronization
Normally, set this to [1st curtain] so that the flash fires immediately
after the exposure starts.
If [2nd curtain] is set, the flash will fire right before the shutter
closes. When this is combined with a slow shutter speed, you can
create a trail of light such as from car headlights at night. With E-TTL
II (autoflash exposure), two flashes will be fired: Once when you
press the shutter button completely, and once immediately before
the exposure ends. Also, with shutter speeds faster than 1/30 sec.,
1st curtain synchronization will automatically take effect.
If an external Speedlite is attached, you can also select [Hi-speed]
(e). For details, refer to the Speedlite's instruction manual.
Flash exposure compensation
See "Flash Exposure Compensation" on page 113.
E-TTL II flash metering
For normal flash exposures, set it to [Evaluative]. [Average] is for
advanced users. As with an external Speedlite, the metering is
averaged for the entire area. Flash exposure compensation may be
necessary.
196
[E-TTL II] is the standard mode of
EX-series Speedlites for automatic
flash shooting.
[Manual flash] enables you to set the
flash output yourself. This is for
advanced users.
Regarding other flash modes, refer to
the instruction manual of an external
Speedlite compatible with the
functions.