Convinced? So what type of strobes do you need to shoot sharks?
POWERFUL WIDE ANGLE ONES!
Strobes come with different angles of coverage and different maximum
The concept is pretty simple.
In order to throw light at your subject, the strobe has to take energy
from the battery pack and force it across a wire or network of wires. The
wires discharge some of this energy in the form of heat and light. There
is only so much energy available in the batteries and the light is
absorbed very quickly by the water so the best way to throw the light as
far and brightly as possible is to make the beam very narrow.
That's not such a good thing
for shark photographers. Sharks are big subjects and we need the light
from the strobe to be released at a wide enough angle to illuminate the
whole animal. So when choosing a strobe you need to look at the angle of
coverage. Ideally it should be above 100 degrees. The wider the better.
The trade off is that the light
is then less concentrated hence the need for the strobe to be as powerful
Beyond 8ft or so most of the
light thrown by the strobes has been absorbed by the water. You can still
light your subject but you will lose the rich colors that you can obtain
when closer. Sharks don't necessarily like coming close to divers and are
notoriously camera shy so its wise to choose a strobe that has enough
output energy to light your subject from a distance.
I haven't used every strobe out
there but there are a few tried and tested models that seem to end up in
many shark photographers dive bags. They're generally unwieldy but will
give better results that smaller models. Ikelite's 200, Sea & Sea's YS
350, and Subtronic's Mega series are all well respected wide angle