Canon D20 - Manual (Page 118)

Flash
118
Just as with the AE lock (p. 101), you can lock the exposure for the flash shots.
Set the flash to h (p. 117).
Lock the flash exposure.
Aim the camera at the subject to shoot with
the exposure locked. With the shutter button
pressed halfway, press the
r button.
X The flash fires, and when ( is displayed, the
flash output level is retained.
To unlock FE, release the shutter button and
press the
r button again. In this case, ( is
no longer displayed.
Compose the shot and shoot.
Shooting with the FE Lock
• FE: Flash Exposure