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Funcionamente del flash TTL
Fig. 7 / Grabado. 7
Fig. 8 / Grabado. 8
TTL-flash mode
subject in snow, may make it necessary to correct
the exposure settings (see 4.1.2).
Modo flash TTL
4.1.1 Automatic TTL fill-in flash in daylight
Most camera models automatically activate the
fill-in flash mode (see the camera's operating
instructions) when in green full auto mode, pro-
gram „P" or programmed image control mode in
daylight.
Fill-in flash overcomes troublesome dense shado-
ws and produces a more balanced exposure bet-
ween subject and background with contre-jour
shots. The camera's computer-controlled metering
system sets the most suitable combination of shut-
ter speed, working aperture and flash output.
In this instance there is no setting or display on
the mecablitz for TTL fill-in flash.
4.1.2 Manual TTL flash exposure correction
The TTL auto flash mode of most cameras is
matched to a 25% degree of light reflection by the
subject (average amount of light reflected by
flash-shot subjects). Consequently, a dark back-
ground that absorbs a great deal of light, or a
bright background that reflects a great deal of
light, can result in under or over exposure, res-
pectively.
To offset this effect (see Table 1) a correction value
can be set on some cameras to manually match
the TTL flash exposure with the photographic
situation. The actual extent of correction depends
on the contrast prevailing between subject and
background! The correction value is set on the
camera. Please refer to the camera's operating
instructions for details concerning settings!
Exposure correction by changing the lens dia-
phragm is not possible because the camera's
22
Ensure that the contre-jour light source does
not shine directly into the lens as this will
mislead the camera's TTL metering system!
A dark subject in front of a bright back-
ground: Positive correction value (approx. 1
to 2 f-stops). Light subject in front of a dark
background: Negative correction value
(approx. 1 to 2 f-stops). Correction value
settings can change the maximum flash
range indicated on the mecablitz LC display
and match it to the given correction value
(depends upon the camera model)!
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