Modeling Flash - Nikon D300 User Manual

Second, each remote flash unit has a little round photocell
sensor on its side that picks up the monitor pre-flashes from
your camera's pop-up flash. Make sure those little sensors are
not blocked or exposed to direct, very bright light while in
use, or they may not be able to see the monitor pre-flashes
from your camera.
Third, if you want to prevent the monitor pre-flashes from
appearing in photographs or causing people to squint, you
need to purchase the optional SG-3IR infrared panel for the
pop-up flash. This infrared panel makes the monitor
pre-flashes mostly invisible to humans and imaging sensors,
yet the remote flash units can still see it and react properly.
Fourth, don't position any of the remote flash units more than
33 feet (10.05m) from the camera. That's the maximum
distance Nikon supports for the D300(S) pop-up flash in
Commander mode.
If these issues bother you, then invest in the Nikon SU-800
Wireless Infrared Controller unit that replaces the pop-up
flash/Commander mode combo. You mount it onto the
Accessory shoe and let it control the remote slaves out to 66
feet (20.10 m) without some of the issues mentioned above.

Modeling Flash

Custom setting e4 (D300S and D300)
(User's Manual – D300S page 289; D300 page 298)
Modeling flash lets you fire a pulse of flashes to help you see
how the light is wrapping around your subject. It works like
modeling lights on studio flash units, except it pulses instead
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