Canon EOS Rebel XT Instruction Manual page 100

Using the Built-in Flash
m4
Flash Exposure Compensation
*
In the same way as normal exposure compensation, you can set
exposure compensation for flash. You can set flash exposure
compensation up to ±2 stops in 1/3-stop increments.
Select [Flash exp comp].
Select the
[02]
tab.
Press the
<
J/i..T
>
key to select [Flash
exp
comp],
then press <8>.
Set the flash exposure
compensation amount.
Press the
< ....
~
>
key to set the
desired amount, then press
<
8
>.
Standard exposure index
,e+_11
Exposure level mark _. _ . _
=.
Decreased
~ ~
Increased
exposure exposure
To cancel the flash exposure
compensation, set the flash exposure
compensation amount back to
<
i
>.
When you press the shutter button
halfway, the
<~>
icon will be
displayed in the viewfinder and on the
LCD panel.
Take the picture.
[l]
The flash exposure compensation amount will remain in effect even after
you turn the power switch to
<OFF>.
The procedure is the same with EX-series Speedlites. The flash
exposure compensation amount can be set with the camera.
100