Nikon SB-400 Manuel D'utilisation page 19

When the subject has a mottled appearance with the flash
light, raise the tilting degree of the flash head.
Illuminated subject in a mottled tone
Depending on the lens' focal length and tilting degree of the flash head, the
bounced light may illuminate the subject in a mottled tone.
• Tilt the flash head 90º and take the shot.
In case the light is not enough
When the flash light is insufficient
When the reflective surface is too far away, the light from Speedlight may be
not enough to illuminate the subject.
• When taking photograph with digital cameras, set the ISO sensitivity higher than
in normal shooting.
• For bounce flash shooting, set the lens' aperture larger (f/3.5, f/4.5 or f/5.6) than
for normal shooting.
• Reduce the distance between the reflective surface and the Speedlight.
Shooting with the flash head tilted up 90º
Shooting with higher ISO sensitivity
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