Nissin i40 Instruction Manual page 18

Functions by Camera setting
You do not need to set the flash unit for these functions.
Rear curtain synchronization
Rear
All modes except Multiple flash mode are available for this sync.
system.
In rear-curtain sync., the flash fires just before the rear curtain close.
By using this function at slow shutter speeds, a moving subject will
appear with such moving marks behind. Refer the operation manual of
the camera for details.
Auto Flash Bracketing
i40 supports this function at A mode and TTL mode.
By setting this function on the camera, you will get continuous flash
pictures in the different exposure effect on each frame. Exposure
compensation ratio, number of picture frame is to be set on the
camera. Refer the operation manual of the camera for details.
Slow Shutter Synchronization
All modes in i40 supports the slow
shutter synchronization.
The flash is controlled at a slow shutter speed to
trace the correct exposure on both the main
subject and back ground in low light conditions or at night.
The slow shutter speed produces a blurring effect of the subject and a
sharp flash beam freeze the moment. A combination of slow shutter
and flash light creates a motion image in the still picture.
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