Olympus AZ-4 Zoom Instructions Manual page 37

In this mode, the flash always fires. Use this mode when performing
backlighting synchro photography, nighttime slow synchro flash photography or
shooting backlit subjects. For normal indoor photography, we recommend flash
AUTO photography to avoid any effects of camera shake.
Press the FILL-IN button inside the mode
cover.
FILL-IN blinks.
* Press it again for cancellation.
Using Fill-in Flash
The flash pops up, and when it has been
charged, you can press the shutter.
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