The invention of portable ﬂash had a tremendous
impact on photography: it opened the night world
to the camera, with compact, easily carried
equipment. Today, electronic ﬂash is standard to all
compact digital cameras, found on many cell phone
cameras, and ﬁtted to the majority of dSLRs.
However, the position of the ﬁtted ﬂash is just about
the worst possible, in terms of the quality of lighting.
Accessory lighting units are a necessity for versatile
and attractive lighting.
Power and recycling
A further problem is that ﬂash built into a camera
relies on the camera’s own batteries for power. To
curb their hunger for energy, built-in ﬂashes are
designed to be low-powered—usually sufﬁcient to
light to a distance of 3–7ft (1–2m) but little further.
In addition, the recycling rates—how quickly the
ﬂash can be ﬁred in sequence—is also limited.
Portable, or accessory, ﬂash units overcome the
limitations of built-in ﬂash by carrying their own
power and circuitry; this makes the units much
larger than compact cameras. Accessory ﬂash units
also offer more control over ﬂash power, direction
of ﬂash, and angle of coverage.
Accessory ﬂashes ﬁt onto the hot shoe, which
combines electrical contacts with a slot that “mates”
with a corresponding, locking part on the bottom
of the ﬂash unit. While the majority of cameras use
a standard hot-shoe design, the contacts may be
speciﬁc to the camera producer, and some
manufacturers—such as Sony—use proprietary hot-
Many portable ﬂash units place the ﬂash on a
swiveling turret so that it can be directed to the
sides, or even backward, according to the nearest
surface for bounce ﬂash (see pp. 82–9). Some offer
a tilting head so that you can point the ﬂash upward,
or downward for close-up work. A fully adjustable
head increases ﬂexibility, so is a must for wedding
and paparazzi photography.
On many ﬂash units you can also adjust the
coverage, or the angle over which light is spread.
This ensures that when you use a wide-angle lens or
Small supplementary ﬂash
Units like this can augment the power
of built-in ﬂash units. It is triggered by
the camera’s own ﬂash, so it does not
need a hot shoe, and adds its output
to that of the camera’s unit. It is an
inexpensive solution to lighting
problems, but control is limited.
Slave ﬂash unit
Slave units can add to the power of
built-in ﬂash units. This unit synchs
with the on-camera ﬂash for the
most accurate exposure, after which
operation is fully automatic. Position
it to one side of the camera to
improve modeling effects.
Powerful on-camera ﬂash
Accessory ﬂash mounted on a
camera’s hot shoe can be sufﬁciently
powerful forall normal needs,
offering a tilt-and-swivel head for
bounce, multiple-exposure facilities,
and focusing aids for working in