User Manual
17
11 Flash synchronisation
11.1 Automatic flash sync-speed control
Depending on the camera model and camera mode, the shutter speed is switched to flash
sync-
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
manual). 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 (see 11.3) 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 ca manual).
11.3 Second curtain synchronisation (REAR)
Various 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 synchronized 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 various cameras the REAR function is not possible in certain operating modes (e.g., in