Flash Synchronisation; Automatic Flash Sync Speed Control; Normal Synchronisation; Second Curtain Synchronisation (Rear) - Metz 50 AF-1 Mode D'emploi

11 Flash synchronisation

11.1 Automatic flash sync speed control

Depending on the camera model and camera mode, the shutter speed is swit-
ched to flash sync speed when flash readiness is reached (see the camera's ope-
rating instructions).
Shutter speeds cannot be set faster than the flash sync speed, or they are swit-
ched automatically to the flash sync speed. Various cameras have a sync speed
range, for example from 1/60 sec to 1/250 sec (see the camera's operating
instructions). The sync speed set by the camera depends on the camera mode,
the ambient light, and the focal length of the lens used.
Shutter speeds slower than the flash sync speed can be set according to the
camera mode and the selected flash synchronisation (see 11.3 and 11.4).
☞ If a camera with a between-the-lens shutter and high-speed synchronisa-
tion (see 11.5) is used, flash sync speed is not controlled automatically.
As a result, the flash can be used at all shutter speeds. If you need the
full light output of the flash unit, you should not select a shutter speed
that is any faster than 1/125 sec.

11.2 Normal synchronisation

In normal synchronisation the flash unit is triggered at the beginning of the shutter
time (first curtain synchronisation). Normal synchronisation is the standard mode
on all cameras. It is suitable for most flash shots.
The camera, depending on the mode being used, is
switched to the flash sync speed. Speeds between
1/30 sec. and 1/125 sec. are customary (see the
camera's operating instructions). No settings are
necessary on the flash unit, nor is there any display for
this mode.

11.3 Second curtain synchronisation (REAR)

Some cameras offer the option of second-curtain synchronisation (REAR), in
which the flash unit is not triggered until the end of the exposure time. This is
particularly advantageous when used with lower shutter speeds (slower than
1/30 sec.) and moving subjects that have their own source of light. With
second-curtain synchronisation, a moving light source will trail a light streak
instead of building one up ahead itself, as it does when
the flash is synchronised with the first shutter curtain. In
this way a „more natural" image of the photographic
situation is produced! Depending on its operating
mode, the camera sets shutter speeds slower than its
sync speed.
On some cameras the REAR function is not possible in certain operating modes
(e.g., certain vari- or subject programs, or with red eye reduction). In these
cases, the REAR mode cannot be selected and/or is automatically cancelled or
ignored (see camera's operating instructions).
The REAR mode is set on the camera (see camera's operating instructions).
There is no display for REAR mode in the flash unit.
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