Nikon Camera N90 - Manual (Page 196)

RED-EYE REDUCTION (for use with SB-25 only)
When shooting people or animals in dim light using a flash, the
subject’s eye may sometimes appear red in color pictures or
white in B&W pictures. The Red-Eye Reduction function
reduces the possibility of “red-eye”,
With this function, before the shutter is released and before the
multi-area sensor's Monitor Pre-flashes, the flash fires three
visible but relatively dim flashes, followed by the main flash
which takes the picture. The three dim preflashes make the
subject’s eye pupils become smaller, thus reducing the
appearance of red-eye.
Red-Eye Reduction can be set in any exposure mode. In the
Portrait Program with Red-Eye Reduction
(Ps
with
r E),
the Red­
Eye Reduction function is automatically set. With other Vari-
Program options, Red-Eye Reduction cannot be set.
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