Nikon D300 User Manual page 280

4. Press the
Here are descriptions of how
illuminator:
▪ On (default) – If the light level is low, the
illuminator
autofocus. This only works in certain modes, though:
1. Single-servo AF
needed
2. Auto-area AF
needed
3. Single-point AF
AF-area mode
point as the selected sensor
▪ Off – The
you in low-light autofocus situations. The camera may
not be able to autofocus in very low light.
My Recommendation: I leave
set to On most of the time. It is only activated when the light
is low enough to need it. However, let me qualify this for
specific circumstances.
If you are trying to take pictures without being noticed, such
as from across the room with a zoom lens or while doing
street photography, you certainly don't want this extremely
bright little light drawing attention when you start autofocus.
Or, you may be shooting wildlife, such as a giant grizzly bear,
and surely don't want to call attention to yourself by shining a
bright light into the old bear's eyes.
OK button to lock in the setting.
lights up to help light the subject enough for
as a
as an
and
if you are using only the center AF
AF-assist illuminator
On or Off affects the
Focus mode
AF-area mode
Dynamic area AF
does not light up to help
Built-in AF-assist illuminator
280
AF-assist
AF-assist
at any time it's
at any time it's
as an