Photo/Video Techniques for Cold, Dark Waters
By:
Bob Michelson (page 2)
Underwater
photographers should treat their diving gear as extensions of
their own skin. This holds especially true where silt, soft mud
or other forms of decomposing materials can be easily churned
up by sloppy bouyancy control.
One quick, easy method is to slowly lower yourself to the bottom,
then using the power inflater on your BCD use short quick bursts
of air until you slowly start feeling yourself being lifted off
the bottom with no finning. You should remain slightly positive
while finning over an area that you wish to photograph - preferably
several feet off the bottom if visibility permits. This prevents
accidental clouding of the site.
Once
locating an area using bouyancy control again, slowly lower yourself
to the bottom. Once on the bottom, slowly vent air from your BCD
until you are neutrally buoyant. You can tell when you have reached
neutral buoyancy by conducting the following exercise. Gently
rest yourself on the bottom. Slowly add, or delete air from your
BCD. You are neutral when you breath in and you slowly begin to
rise and be exhaling, you slowly start to descend back to the
bottom.
An extra couple of pounds will assist in stabilizing once you
have found the spot for picture-taking, especially in an area
known for surge. But don't overdo it. A little added weight will
not adversely affect neutral bouyancy with today's BC lift capabilities
or create any dive-related safety problems. Experiment in shallow,
protected waters to find a total weight that you feel comfortable
with before venturing out into deeper water.
There are four types of photography that can be employed in cold
waters include wide-angle; normal; close-up; and finally, macro,
with macro being the easiest to accomplish.
Wide-angle photography is indeed a challenge in all cold/turbid
water regions. The largest single problem is one of backscatter
created from a poorly placed strobe. A relatively simple solution
-which will take some practice - is to hand-hold the strobe off
either side or on top of the camera by a couple of feet and at
an angle between 45 and 90 degrees to the camera lens. This technique
works because all suspended particles will be lit from a side
that the camera lens will not see, yielding much less backscatter
in the photo yet still illuminating your subject.
Using
15mm, or 20mm lens with a Nikonos, or a 20mm lens with an SLR
in a housing, will force you to move in close to the subject,
which will also help reduce backscatter by simply reducing the
amount of suspended particles between the subject and camera in
the water column.
To
enhance the look of the photo, try to increase the degree of green-water
column in the background. This can be accomplished by first placing
the sun directly behind the main subject when possible.
Second,
when using a warm-toned film such as Kodachrome 64 ASA, set the
shutter speed at either M 1/90 second with a Nikonos -or whatever
the slowest synch shutter speed is for your SLR when using a strobe
(1/60, 1/125). Set the F-stop to F4 or 5.6 when at 30 feet with
average visibility of perhaps 20 feet. Simply place the strobe
at the proper angle and bracket exposures three to four stops.
Adjust the strobe power output over several dives to gain a pleasing
balance of ambient green-water column and fill flash on the main
subject.
Of course, aperture adjustments will have to be made for shallower
or deeper water, as well as for increase or decrease of visibility,
but the same technique will still apply. With a little experimentation,
good wide-angle photos are a real possibility in cold/turbid waters.
General,
or normal lens photography is a second option for photographers.
This would include the built-in lens on any underwater photo system
you purchase. Lens focal lengths range from 35mm to 50mm (slightly
wide angle to normal when using the 35mm format). This type of
lens is good for shooting diver portraits and some mid-ranged
diver interaction photographs. Wide angle lens of between 15mm
to 28mm (35mm equivalent) are strongly recommended verses the
normal lens packaged with a camera. Wider angles of coverage force
photographers to get closer to their subjects, hence removing
water column and suspended particles from the shot.
Close-up
photography is the third option and is most beneficial for acquiring
good fish portraits, especially under restrictive visibility such
as during a night dive or very poor visibility during the day.
The large rectangular framer and a Nikonos camera combines to
clearly target where the subject should be situated before taking
the shot, without having to look through the camera eyepiece viewfinder.
There are also several aiming devices available so you do not
have to use the framer that comes packaged with a Close-up kit,
which tends to frighten potential subjects.
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