Most point & shoot style digital cameras
lack hot shoes and any means to fire a second flash unit. But a bracket-type
flash that has a built-in slave sensor can be used to fire in sync with the
camera's flash. Since digital cameras usually fire a series to flash bursts
(to set focus, white balance, etc.) prior to the main burst of light, this
slave flash should have a "smart" sensor. This type of sensor will ignore
the pre-flashes and fire in sync with the primary burst of light.
A fully dedicated flash will interface with
the camera's auto focus and auto-exposure system, while producing
considerably more light for greater range and with more creative control
than the built-in flash.
A studio flash system with multiple flashes
on light stands can be used with digital cameras.
The primary issues are synchronizing the
camera with the flashes and controlling exposure. Ideally, the camera will
have a PC flash cord terminal or a hot shoe with a cord adapter to fire the
Otherwise the built-in flash can be used to
trigger the slave-equipped studio flash.
The camera will need to have a flash mode
that doesn't use pre-flashes, or a "smart" slave that ignores pre-flashes
will need to be used. The camera will need to have manual exposure control
so the exposure and light output from the studio flash can be balanced.
Ordinary flash units will
not work because your digital camera lacks a way to connect and/or mount an
external flash. Even more importantly, most digital cameras emit a “pre-
flash” and/or a ‘red-eye” pulse that fire before the shutter opens, then an
additional flash pulse is fired to actually light your picture. This
“pre-flash” (“double-flash”) and/or “red-eye” pulse confuses other flash and
slave units , causing them to go off at the wrong time, and are useless for
your digital camera.
The Slave Flash has
special digital pulse counting slave circuitry that is not fooled by the
“pre-flash” and eliminates the need for an electrical connection to your
camera. A three-position switch sets the flash to ignore one or two
“pre-flashes”, or none at all.
in built in flash units of digital cameras are on average effective to only
about 12 feet, and that's when your lens is at its widest-angle setting.
When you want to zoom in on the action (towards the telephoto end of your
zoom range) you'll find that your built in flash does exactly opposite of
what you want, its range is reduced to about 8 feet, and sometimes even
less! So, when you want to use your camera's telephoto capability that you
paid for, but also require the built in flash, your pictures come out dark
or, even worse, not at all.