Second Curtain Flash

IT’S ABOUT WHEN THE FLASH
fires. With inexpensive cameras or
flash units, you don’t have a choice:
The flash is synced to fire as soon as
the shutter (i.e., “curtain”) opens.
With mid- and higher-level gear,
however, it’s your choice: You can
trigger the flash as the shutter opens
(first-curtain) or wait until just
before it closes (second-, rear-, or
trailing-curtain sync).
What difference does it make? For
90 percent of your flash photos, it
won’t make any difference. But for
flash photos of moving subjects shot
against dark backgrounds, such as
cars at night or dancers flying across
a darkened stage, choosing the cor-

rect syncing option can make the
difference between an image that
looks natural, and one that seems
freakishly wrong.
The problem? If you use first-curtain
sync with a moving subject, the
blur that defines the movement can
precede the object instead of trailing it.
It gives the impression that the object
is going backward, not forward.
Second-curtain sync places the blur
behind the object where it belongs.
Some systems set second-curtain
sync in the camera, some in the flash,
and some offer both. In most cases,
the flash’s settings override those of

the camera. If the camera is set to
first-curtain sync, for example, and
the flash to second, you get the latter.
So if movement looks more natural
with second-curtain sync, why is
first the norm? One reason is portraiture.
If you’re shooting a child in
low light, say, and you’re trying to
catch a fleeting smile, you don’t
want the flash to fire a fraction of a
second late, do you?

~ by paragonhost on March 28, 2007.