Flash Synchronisation; Normal Synchronisation; Second Curtain Synchronisation (Rear Mode); Slow Synchronisation / Slow - Metz MECABLITZ 58 AF-2 digital Mode D'emploi

17 Flash synchronisation

17.1 Normal synchronisation

In normal synchronisation the flash unit is triggered at the beginning of the shut-
ter 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.

17.2 Second curtain synchronisation (rear mode)

Some cameras offer the option of second-curtain synchronisation (rear mode),
in which the flash unit is not triggered until the end of the exposure time. This is
particularly advantageous when used with slow 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 of itself, as it does when the
flash is synchronised with the first shutter curtain.
Second-curtain synchronisation thus produces a more
„natural" image of the photographic situation when the-
re are moving light sources. 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 that case,
the rear mode cannot be selected, or the rear function is automatically cancelled
or ignored. For more information, refer to the camera's operating instructions.
• The „REAR ON" setting is for second curtain synchronisation.
• The „REAR OFF" setting is for normal synchronisation.
☞ The REAR function can be selected and set in the flash unit's Select Menu
only when the flash unit is operated with a suitable Group B camera
(Table 1). The REAR mode is indicated on the flash unit only when it has
been set on the flash unit.

17.3 Slow synchronisation / SLOW

Various cameras feature slow flash synchronisation in certain modes. This setting
will give added prominence to the background at lower ambient light levels. This
is achieved by matching the shutter speed to the ambient light. Accordingly, shut-
ter speeds that are slower than the flash sync speed are automatically adjusted
by the camera. Some cameras automatically activate SLOW synchronisation in
connection with certain camera programs (e.g. „Av" aperture priority, night
shots program, etc.). No settings are made on the flash unit nor is there any
display for this mode.
☞ Use a tripod to avoid camera shake with slow shutter speeds!

17.4 Automatic high speed synchronisation HSS

Various cameras support the automatic high speed synchronisation HSS (see
your 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 be achieved in this mode when, for example, a wide open
aperture (e.g., F 2.0) is used to limit the depth of field. The flash unit supports
high speed synchronisation in E-TTL (E-TTL HSS) and M modes (M HSS).
For physical reasons, however, HSS high speed synchronisation significantly
reduces the guide number and the maximum range of the flash unit. Therefore,
be sure to note the maximum flash range on the LC display of the flash unit. HSS
high speed synchronisation is activated automatically if a shutter speed faster
than the flash sync speed is set on the camera, whether manually or automatical-
ly by the exposure program.
☞ Note that in the case of HSS high-speed synchronisation the guide num-
ber of the flash unit also depends on the shutter speed. The faster the
shutter speed, the lower the guide number. The settings are made in the
Mode menu.
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