AD 2016 Q1

IMAGING
PHOTO TECHNIQUES
of strobes and LED lights endeavor to achieve a color
temperature near daylight balance (approximately 5500-
6000K). In our experience, most brands of underwater
LED lights tend to be slightly warmer than strobes, but
minor temperature adjustments are easy to perform
using basic postprocessing software.
CONSIDERATIONS AND TECHNIQUES
In recent years a variety of LED lights created
specifically for underwater imaging have become
available, and the technology is continually and rapidly
improving. The dazzlingly bright 14,000-lumen lights
we used in Bonaire in 2015 were a far cry from the 500-
lumen lights we first used for still imaging less than five
years ago. While currently available LED lights are easily
capable of illuminating a subject for still photography,
they still lack the pop of power offered by many
strobes. As a result, one of the key tenets of underwater
photography becomes especially important when
substituting the former for the latter: Get close.
Decreasing the distance to your subject will help your
LED lights produce excellent foreground exposure, even
in wide-angle scenes. To this end, using photographic
equipment that permits very close focus, such as shortfocal-length
macro lenses or fisheye wide-angle lenses,
is critical. It is often necessary to use a wider aperture
with LED lights than one might choose when using
strobes, and depending upon the strength of your lights
and their beam width, it might be necessary to choose
a smaller subject (such as a single branch of soft coral)
as opposed to a larger one (such as a large rock covered
with soft coral).
The relative limits of currently available LED lights
may also affect composition. Whereas when using
strobes we generally endeavor to approach subjects
from below and shoot toward the ocean’s surface, LED
lights do not always have the power to compensate for
the faster shutter speeds sometimes required in bright
conditions. For now, images featuring tight sunballs
are far more likely to be achieved using strobes than a
continuous light source.
Another consideration is your subject’s comfort. We
can attest through firsthand experience that certain
subjects (especially models) might become annoyed
quickly when asked to pose facing blindingly bright
continuous lights. And while some marine life won’t be
bothered, there is simply no way to stealthily approach
an animal with thousands of lumens of light continually
emerging from your camera rig — and a shy species
may not pose for even the briefest shot. Since burn time
is a major limitation of currently available lights, you
are unlikely to be swimming around with your lights
constantly powered on, but even going through the
motions of turning on your lights may disrupt some
types of marine life. Although the compact size and light
weight offered by some LED lights can be advantageous
for travel, recent Federal Aviation Administration
recommendations against packing lithium-ion batteries
in checked luggage could mean adjusting your carry-on
baggage plans to accommodate them.
ADVANTAGES
There are lots of advantages to using LED lights
for still imaging. The ability to shift between video
and still photography during a single dive without
carrying multiple light sources (or worse yet, multiple
dedicated camera systems) is the most obvious, and
it’s a biggie. Many, if not most, cameras are capable
of both formats, and the flexibility offered by a strong
continuous light source might handily outweigh any
disadvantages.
In many cases, LED lights are smaller and/or lighter
than strobes, providing a size/weight advantage that
is particularly beneficial when diving from shore,
in current or in confined spaces. LED lights also
help optimize autofocus in dark conditions, allow
visualization of colors at depth and permit real-time
adjustments that decrease the need for in-water image
review, which means more time to capture images.
While bracketing remains a good idea, photographers
can use the light meter during shot setup to detect any
major exposure problems and correct any unwanted
highlights or shadows before releasing the shutter.
The same goes for detection of backscatter or flare:
Issues can be spotted easily through the viewfinder,
which helps to diminish unpleasant surprises during
image review (or worse yet, time-consuming processing
obligations after download). Photographers using
continuous light sources also have fewer shutter-speed
limitations compared with strobe users, because they
don’t have to be concerned about synchronization or
ghosting issues resulting from too-fast or too-slow
shutter speeds, respectively.
CONCLUSION
Rapid, enormous advances in LED technology have
given rise to a variety of compact, high-intensity lighting
options for underwater image-makers. As a result,
the use of LED lights in still imaging has become a
useful illumination technique, allowing quick transition
between videography and still photography and thus
permitting shooters to choose how to document a
subject during their dive. Certainly, there are differences
between using strobes and LED lights for still imaging,
104 | WINTER 2016