Nikon autofocus speedlight SB-900 User Manual page 90

Wireless multiple flash shooting
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Notes on performing wireless multiple fl ash photography
• To avoid accidental firing, turn off the camera and all flash units before
mounting the master flash unit on or connecting it to the camera.
• The master flash unit cannot be test-fired.
• The brightness of the flash illumination is inversely proportional to
the square of the distance between the flash unit and the subject. For
example, if the distance between Speedlight A and the subject is 1 m
(3.3 ft.), and Speedlight B is 2 m (6.6 ft.) and both A and B have the same
guide numbers, the combined brightness of the two Speedlights will be:
A : B = 1 : 4 (in meters) or approx. 11 : 44 (in feet)
• See the user's manuals of your cameras and Speedlights.
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Notes on remote flash
Take care of the following.
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Notes on setting a remote fl ash unit
• When using a Speedlight that has a standby function as a remote flash
unit, make sure that the standby function is set to "OFF," or select a
standby duration that is long enough in the custom setting.
• The standby function of the SB-900, SB-800, SB-700, SB-600 and SB-80DX is
canceled when wireless remote flash mode is set. Make sure that there is
sufficient battery power.
• The SB-50DX's standby duration is automatically extended to approx.
one hour when it is set to wireless remote flash mode.
• Set the angle of coverage of the remote flash units wider than the
picture angle, so that the subject will receive sufficient illumination even
when the angle of the flash head is off axis from the subject. When the
flash-to-subject distance is very short, set the angle of coverage wide
enough to achieve sufficient light.
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Notes on setting up the remote fl ash units
• In most cases, position the remote flash unit(s) closer to the subject than
the camera, so that light from the master flash unit can reach the light
sensor of the remote flash unit(s). This is particularly important when
holding a remote flash unit in your hand.
• Data communication cannot be performed properly if there is an
obstacle between the master unit and remote flash units.
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