Preflashes For Red-Eye Reduction - Metz MECABLITZ 28 AF-3 Canon Bedienungsanleitung

Maximum flash range indication in TTL flash mode
The flash unit's LC display indicates the maximum
flash range. The indicated value relates to a factor
of 25 % of light reflection by the subject, which
applies to most photographic situations. Pro-
nounced deviations from this reflection factor, e.g.
with highly reflective or poorly reflecting objects,
can influence the maximum flash range of the
flash unit.
Always observe the maximum flash range indi-
cated by the flash unit's LC display. The subject
should be within approx. 40 % and 70 % of the
indicated value. This gives the electronic circuit
sufficient scope for compensation. To avoid over-
exposure, the minimum flash-to-subject distance
should not be less than 10 % of the indicated
value. Adaptation to the given photographic situa-
tion is possible by changing the aperture setting
on the lens.
Maximum flash range indication in the manual
flash modes M and MLo
The flash unit's LC display indicates the distance to
be maintained for correct exposure of the subject.
Adaptation to the given photographic situation is
achieved by changing the aperture setting on the
lens and selecting either "M" for full light output or
"MLo" for partial light output (P 1/8) (see 4.6).
Exceeding the display range
The LC display of the flash unit can indicate a ma-
ximum range of 199 m or 199 ft. The display
range of feet (ft) may be exceeded in the event of
high ISO values and large aperture openings. This
is signalised by the flashing of "199ft".

5.8 Preflashes 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 ambient light is rela-
tively dark, and the flash unit is mounted on or
directly next to the camera. The flash unit illumi-
nates 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 facility brings about a signi-
ficant improvement in this respect. When this func-
tion is used, the flash unit will fire one or more
weakly visible preflashes (depending on the
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