Twenty
five years ago, I quit my humdrum clock card punching day job
to pursue a career that had fascinated me since childhood. Having
been born and raised in a small fishing village in Edinburgh,
Scotland, the ocean and all it's wonders had always held a fascination
for me.
During my impressionable years,
my old grandfather had passed on a piece of advice. "Pick
something you love doing son, make it your job and you will never
have to work a day in your life". I must admit, at the time
I had no idea as to the wisdom of his words but having since
put them into practice, I am now forever grateful to the old
guy.
Working as a Scuba Diving Instructor
kept my excitement quotient high through the early 80's, but
invariably I began to look for a new challenge. My employer at
that time owned an old Sony TR81 8 m/m video camera, so after
some searching I managed to come up with an underwater housing
of sorts and with tools in hand, headed down a path that has
turned into a never ending quest for superior quality underwater
video footage.
As most TV audiences are aware,
there is a wide variety of quality and craftsmanship in the the
underwater footage that they see on TV.
Sometimes the reason for this is
economics. If the producer is stretched to his or her budget
limits, the inexpensive way to go is the purchase of any underwater
footage that happens to be available in that particular area
of the world. The footage is usually gleaned from local video
enthusiast's results at the resort where the film crew are based
for the shoot. Rather than running over budget by attempting
to shoot their own stuff, they rely on the fact that most people
won't be able to tell the difference anyway. (good underwater
video equipment and skilled videographers don't come cheap).
Once the already sub standard footage
hits the editing phase, nine times out of ten the editor who
is in charge of chopping it up has no idea what a coral reef
looks like and after throwing on a few filters and dissolves,
is quite pleased with his or her creation. After all, there are
bubbles in the scene so everyone must know that it's underwater,
right?
As in any videography, there are
two distinct areas we have to contend with in producing a quality
result. "Equipment" and "Technique", but
unlike topside where the latter can sometimes compensate for
a lack of the former, both are equally important in the underwater
application. A leak in the video housing and the best technique
in the world goes down the tubes at a very high rate of speed.
So let's begin by developing an understanding of the necessary
hardware.
There are more than a few people under the impression that the
video manufacturers such as Sony etc. must produce some kind
of underwater camera. I've come across this line of thought quite
a few times over the years. One of the first things to understand
is that this is "not" the case. I'm pretty sure that
if you check your warranty on your PD150 or XL1, you will find
that there is a clause which states that if you do subject it
to moisture, you will be heading to your bank for overdraft coverage.
The manufacturer definitely did not take into account the fact
that you wanted to take their product underwater.
Hanging on the fringe of the video
camera manufacturer's coat tail's are a number of companies who
will gladly accommodate the underwater enthusiast. Some of their
products work well and then again, some of them don't. The trick
is in being able to distinguish what works and what doesn't.
While you are in the process of pouring the salt water from your
video housing onto the deck of the dive boat and your XL1 battery
has fused to the camera body, it's definitely not the right time
to do some research on the effects of salt water and electrolysis.
All the underwater housings on the market fall into two categories.
For want of a more technical designation, let's call them the
"solid" and the "see through".
The solid housings are usually
constructed from an aluminium alloy, (or aluminum as you folks
south of the border like to call it) and have the characteristic
that the user cannot see what is going on inside. Therefore being
unaccesible, the buttons and switches on the camera are useless.
The way the housing manufacturer gets over this problem is by
transferring the electronics, via a remote cable to buttons and
switches on the outside of the underwater housing.
My personal experience with this
type of underwater housing is less than satisfactory. Seeing
as I intend using the piece of equipment primarily in a part
of the world that inherently has high humidity and salt sea air,
I have discovered that they develop moisture problems, usually
around the third day of the trip. No matter how attentive a person
is, the little chip board on the inside of the housing soaks
up all that moist air and I'm in for a bunch of problems. I've
lost track of the number of divers I've encountered with a tear
in their eye reporting that their video camera just would not
power up underwater, or that the record/pause function bit the
big one.
The other consideration with this
type of housing is that it relies on a "leak detector",
in the form of a small warning light on the outside of the housing,
designed to let you know that you are a candidate for a bank
loan. Now with my limited knowledge of electricity, I can understand
that if I introduce water to an electrical circuit, it will invariably
short out and that's just what happens to these little gizmo's.
If this transpires, I'll continue on my underwater excursion
until such time as I notice water slopping around in the viewfinder.
This invariable produces a painful sensation akin to a mother
undergoing childbirth.
In comparison, the "see through" type of underwater
housing is by far, a more trouble free setup and is my own personal
choice.
Made from a clear Lexan material,
the buttons and switches on the housed video camera are accessed
through control rods which pass through the outer body. No electronic
remote cables and leak detectors to worry about. I simply have
to concern myself with keeping the video camera dry and functional
and forget about remote features going belly up.
When it comes to the possibility
of a bad O-ring seal, it's a simple procedure to adopt the habit
of "visually" checking that all is well inside. This
should always be done in the first few feet of water after jumping
from a dive boat. Spinning the housing around and checking for
bubbles becomes a routine and if by some chance a leak is detected,
I have more than enough time to climb back on the boat and save
the video camera. It is secured to a plate approximately one
inch above the bottom of the housing, so even although there
is a cupful of water inside, as long as I keep the housing level
I can save the day. I may add that in 15 years, I have never
had this happen. (touch wood).
Not adhering to this preliminary
step is one of the main reasons for flooded housings. As we descend,
the water pressure increases and what began as a few drips in
shallow water progresses at depth to the equivalent of switching
on your garden hose inside the housing. Say goodbye to your video
camera.
Now we have to turn our attention to the subject of what it takes
to record all these wonderful colors onto the camera tape.
To see colors, our eyes need light.
That's a simple fact. So we have to be aware of what happens
to light underwater. Even in very clear water, the light rays
from the surface are absorbed in the first 20 feet or so and
even although we can still see very clearly in the deeper water,
most of the bright colors have been filtered out of the spectrum.
The first ones to vanish are at the upper end, the red's and
yellow's.
Now as a result of the camera seeing
what our eyes see, our footage starts to take on a very cold,
dismal persona. The captured colors are anywhere from blue through
green and anywhere from black through white. All the warm colors
of the rainbow are gone.
We have two ways to counteract
this, the first one being color correction filters. Positioned
over the front dome port of the housing, they assist in putting
back those colors which have been filtered out by the water.
There is however a limitation to this way of fooling the camera
lens. The filter works anywhere between 20 and 80 feet, optimum
depth around 50 feet.
Shallower than this range, they
are overpowered by the ambient light and the resulting footage
gives the impression that someone has spilled a bucket of red
ink into the water. A pink tinge to our footage maybe has some
use if your subject is flower gardens, but doesn't have any place
in the underwater application.
Deeper than this range, and your
subject looks like it has virtually started to bleed. Everything,
including the water turns to bright red. This kind of footage
has only one place in my underwater library and comes under the
heading of never to be seen again with the naked eye. I save
a few clips of my own mistakes and use them when teaching an
underwater videography course to show what happens deeper than
80 feet.
In addition to the color correction filter, we can introduce
artificial light to the subject which will put the red's and
yellow's back where they belong. But as in studio lighting topside,
we can mess up underwater video footage very quickly if we position
the lights badly.
A diffused beam is of primary importance.
Most divers have an underwater light for poking around in crevices,
but this type of light is useless for illuminating a subject.
The penetrating beam of the dive light throws an enormous hot
spot, especially if the subject is partially white in color.
My own angle of attack is two 100
watt light heads, one on each side of the housing. One is positioned
to illuminate the foreground subject and the other is deflected
towards the background. This technique gives a far better result
than blasting the poor little fishy with 200 watts of light at
close range.
Last but not least in the equipment
department, we have to be concerned with the additional complication
of focusing the lens through water. Everything underwater is
magnified by a factor of one third and the light rays striking
the lens have been bent somewhat. It's known as refraction.
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