Olympus 170 - Manual (Page 36)

FILL-IN FLASH
(Forced Activation)
When you want the flash to
fire for each shot.
The flash fires regardless of
available light. Use this mode to
compensate for a shadow cast
on the subject's face (such as
the shadow of a tree). It is also
used when shooting in backlit
conditions or under artificial
lighting (such as fluorescent
light). Use this mode within the
flash working range (p. 32).
Closing the lens barrier restores
the Auto Flash mode.
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