High Speed Sync Flash Mode - Leica R9 Instructions Manual

High speed sync flash mode

(With appropriately equipped flash units
(with HSS mode/s) and SCA 3502M3 adapter)
Alongside the flash photography described, with
shutter speeds up to the sync speed of 1/250 s,
the LEICA R9 also allows the flash to be used
with all faster shutter speeds from 1/350 s to
1/8000 s. This flash technology opens up new
opportunities for daylight fill-in flash, e.g. if, with
a high level of brightness, you want to take pho-
tographs with an open aperture for picture com-
position reasons, or you want to "freeze" a rapid
movement.
The technology:
With traditional flash technology, the flash expo-
sure is made by the emission of a – controlled or
uncontrolled – flash burst, whose reflected light
can expose the entire image field when the shut-
ter is open.
With focal plane shutters like those on the LEICA R9,
however, the shutter window is only completely
open for a brief moment up to a particular time –
the sync speed.
Shorter exposure speeds can only be achieved if
the 2 shutter curtain is already moving before
nd
the 1 st has completely opened the shutter win-
dow. As a consequence, the shutter window for
shutter speeds faster than this sync time cannot
be completely reached by a single flash at any
time.
By contrast, in high speed sync flash mode the
emission of several flashes in rapid succession
creates an effect similar to that of a constant
light source, exposing the entire shutter window
evenly while the shutter is moving.
High speed sync flash is possible with either
manual or TTL flash control, as well as in the
camera exposure modes m and A .
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