Automatic High-Speed Synchronisation ( Hss); Manual Flash Exposure Correction - Metz Mecablitz 52 AF-1 Sony digital Bedienungsanleitung

7.4 Automatic high-speed
synchronisation ( HSS)
Various cameras support automatic
high-speed synchronisation HSS (see the
camera's operating instructions). This flash
mode makes it possible to use a flash unit
even with shutter speeds that are faster than
the flash sync speed.
Interesting results may by achieved in this
mode when, for example, a wide open
aperture (e.g., f/2.0) is used to limit the
depth of field in portrait shots taken in very
bright ambient light. The flash unit supports
high-speed synchronisation in
flash modes.For physical reasons, however,
high-speed synchronisation significantly
reduces the number and the maximum flash
range!
Be sure to note, therefore, the flash range
on the display of the flash unit. High-speed
synchronisation is activated automatically
if a shutter speed faster than the flash sync
speed is set on the camera, whether
manually or automatically by the exposure
program.
Note that in the case of high speed synchro-
nisation the guide number of the flash unit
also depends on the shutter speed.
The faster the shutter speed, the lower the
guide number!
TTL M
and
High-speed synchronisation is activated
automatically if a shutter speed faster than
the flash sync speed is set on the camera,
whether manually or automatically by the
exposure program.
8 Manual flash exposure
correction
The auto flash exposure mode of most
cameras is adjusted to a reflection factor of
25% (the average reflection factor of flash
subjects).
A dark background that absorbs much of the
light or a highly reflective bright background
(backlit shots, for example) may result in,
respectively, underexposure or overexposure
of the subject.
To offset these effects, the flash exposure
can be adjusted manually for the shot with a
correction value. The extent of the correction
depends on the contrast between the subject
and background!
In TTL flash modes, manual flash exposure
correction factors of from -3 EV (f-stops) to
+3 EV (f-stops) can be adjusted on the flash
unit in one-third increments.
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