The maximum flash range will not be indica-
ted when the flash unit’s reflector is swivelled
or tilted or when the flash unit is in cordless
Metz Remote Mode.
Depending on the type of flash unit used, the ISO
sensitivity and the aperture may be indicated. On
some camera models the indicated values may
deviate from the camera settings. These, however,
are insignificant for the TTL flash mode and need
not be corrected manuallly.
4.8 Preflash function for red-eye reduction
Red eyes are always the result of a physical
effect. This arises whenever a person looks more
or less straight into the camera, the ambien light
is relatively dark and the flash unit is mounted on
or directly next to the camera. The flash unit illu-
minates the back of the eyes, revealing the blood
filled retina through the pupil. This is recorded by
the camera as a red spot in the eyes.
The red-eye reduction function brings about a sig-
nificant improvement in this respect. When this
facility is used the flash unit triggers, prior to shut-
ter operation, a few weakly visible preflashes
which are followed by the main flash. These pre-
flashes induce the pupils to close down, thereby
diminishing the red-eye effect.
The preflash function is set on the camera and in-
dicated by a corresponding symbol (see camera
manual).
On various cameras, second-curtain synchro-
nisation (REAR) will not be performed when
the preflash function is activated.
Some cameras will support the preflash func-
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