Canon EOS REBEL EOS T5 1200D Instruction Manual page 394

The built-in flash is raised by itself.
In shooting modes (<A> <
settings are <
when necessary.
The built-in flash does not fire.
If you shoot continuously with the built-in flash at short intervals, the
flash may stop firing to protect the flash unit.
The flash always fires at full output.
If you use a flash unit other than an EX-series Speedlite, the flash will
always be fired at full output (p.271).
Under [z1: Flash control], if [Flash metering mode] for [External
flash C.Fn setting] is set to [TTL], the flash will always fire at full
output (p.197).
I cannot set flash exposure compensation when
using an external Speedlite.
If flash exposure compensation has already been set with the external
Speedlite, flash exposure compensation cannot be set with the
camera. When the external Speedlite's flash exposure compensation
is canceled (set to 0), flash exposure compensation can be set with
the camera.
High-speed sync cannot be set in the <f> mode.
Under [53: Custom Functions (C.Fn)], set [3: Flash sync. speed in
Av mode] to [0: Auto] (p.259).
C
> (Auto flash), the built-in flash will rise automatically
a
> <2> <4> <6>) whose default
Troubleshooting Guide
289