13 Flash synchronisation
13.1 Automatic flash sync speed control
Depending on the camera model and camera
mode, the shutter speed is switched to flash
sync speed when flash readiness is reached
(see the camera's operating instructions).
Shutter speeds cannot be set faster than
the flash sync speed, or they are switched
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
k
mode and the selected flash synchronisa-
tion.
If a camera with a between-the-lens shutter
and high-speed synchronisation (see 7.4)
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.
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13.2 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.
13.3 Slow synchronisation (SLOW)
A slow exposure (SLOW) gives added
prominence to the image background at
lower ambient light levels. This is achieved
by adjusting the shutter speed to the
ambient light. Accordingly, shutter speeds
that are slower than the flash sync speed
(e.g., shutter speeds up to 30 sec.) are
automatically adjusted by the camera. Slow
synchronisation is activated automatically on
some camera models in connection with
certain camera programs (e.g., a night shot
program, etc.), or it can be set on the camera
(see the camera's operating instructions).
No settings are necessary on the flash unit,
nor is there any display for this mode.