Olympus Accura Zoom 105R - Manual (Page 34)

FILL-IN (Forced Activation)
When you want to fire the flash every shot.
In the FILL-IN Flash mode, the flash fires regardless of
available light. For example, this mode can be used to
brighten up a subject's shaded face or under artificial
lighting such as back-lit, fluorescent light. Use this
mode within the flash working range (p. 31).
It may be hard to work under the excessively bright
light.
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