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Shooting Underwater
Videos
Going and Videoing Under Water
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| Before making your first underwater video you must learn to SCUBA dive,
as it isn't possible to shoot much video using a snorkel. Visit www.bsac.com
or www.padi.com and look up "Divers" in Yellow Pages for details of diving
schools near you; just learning the basics is inexpensive and not too difficult.
But this is not enough, you need to become a very competent diver, and your
buoyancy control needs to be exceptional. Buoyancy control is the ability
to remain stationary at a given depth or to ascend or descend simply by
controlling your rate and depth of breathing. |
SCUBA = Self Contained Underwater Breathing
Apparatus. Recreational divers breath compressed air or oxygen-enriched air
called Nitrox.
BSAC = British Sub Aqua Club operates clubs not unlike cine clubs
where training is available at modest cost but may extend one-night-a-week
over several months.
PADI = Professional Association of Dive Instructors operates on a
franchise basis internationally. Its courses cost more but each stage in
training can usually be completed in a few days. It is possible to do the
theory course in UK and the practical part on holiday in warmer waters! |
You can hire all the kit at dive centres in most resorts
for a modest fee but experienced divers prefer to use their own:
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wet-suit and boots
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fins (not "flippers" please)
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watch-style dive computer (which tells you how long you may safely stay under
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mask
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BCD (Buoyancy Control Device) the jacket-like garment which harnesses all
your kit neatly and has inflatable pockets which help adjust your buoyancy
in the water.
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Regulator: This allows you to breathe the compressed air from the tank.
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At many dive sites you will be reprimanded if you make any contact with
the coral or even the sand bottom. To develop personal confidence you should
aim to reach PADI Rescue Diver or BSAC Dive Leader grading. Under water you
will breathe compressed air or preferably oxygen-enriched air (Nitrox) if
this is available and you are suitably qualified. Nitrox allows greater time
at medium depth and theoretically more dives per day. To get the maximum
time under water you must use a dive computer. To benefit from Nitrox, you
must use a Nitrox rated computer. Total equipment costs for warm water diving
will be around £1000, you always use air tanks and weights supplied
by the dive centre. |
Most people do not live near a coastal site with acceptable underwater
visibility. In my case it's about 250 miles away, and so videoing is done
mainly while on holiday. For me, holiday implies tropical waters and that
can imply from £80 to £300 per diving day. |
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When diving, you always dive with a "buddy". Unless you are
very experienced, your holiday dive centre you will ask you and your buddy
to dive within a group of buddy-pairs led by a Dive Guide. Group diving is
a nuisance as the other divers and their exhalation bubbles will get in your
way; just one bubble on your lens will render any footage unusable. Some
of the divers may be photographers with camera mounted flashguns. The blinding
flashes of light will ruin your footage and may scare off many of the larger
creatures. You therefore need to be on your own, with of course your
long-suffering buddy who knows by now when to stop exhaling.
So start now on your quest to become "very experienced". An alternative
possibility to group diving and available at some dive centres is to hire
your own diveguide. Special trips for groups of videographers would be ideal
but don't seem to be available, perhaps because there are relatively few
underwater videographers. Or perhaps nobody has thought about arranging them! |
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| Dive times around the UK will be limited to about 40 minutes, whilst
at warm water sites they will usually extend to one hour. At some centres
you may be limited to just two dives a day, on a liveaboard it may be possible
to cram in five dives per day. Your maximum depth will usually be limited
to 40 metres where there is little light, so you will often choose to spend
most of the dive above 20 metres. |
Liveaboard = a boat equipped with cabins (often
air-conditioned), showers, toilets, galley and dive gear such as an air
compressor. These take groups of divers for trips of several days length.
The crew help look after the gear, cook and are responsible for navigation
and some safety issues. All the waking hours are available for diving, but
underwater time must be balanced by time above water as laid down in safety
rules. |
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Under water, the environment and the creatures that you wish to video
will control your possibilities in a variety ways. Different creatures may
live only at specific depths, so that is where you must dive to see them.
You have to understand the environment, learn to use it to your advantage,
and take steps to overcome the obstacles it presents.
The sea is very rarely still. If you and your subject are moving together
in a surge, the subject will stay central in your video. But the background
will oscillate and make the viewer feel seasick. If you must video in a surge
you must use a tripod and select subjects that do not move. Remember to dry
and grease your tripod after use, they corrode very rapidly in sea water. |
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| To fin = to swim using legs augmented with fins. Divers
rarely use their arms for propulsion.
Reef hook = hook-like device used to fasten the diver to a rocky part of
a reef. With the present emphasis on protecting fragile coral these are often
encouraged but are normally used only by experienced divers who can avoid
damage. |
It is possible to fin into a current of about 1 knot and to maintain
position with a stationary subject. Or you can stop finning and let the water
take you and film on the move. This can be successful, but only for small
sections of the total video. Reef hooks are useful and allow you to remain
stationary above the reef in quite strong currents. |
But best
of all is to choose sites where the current is weak and staying still is
not a problem.
The other most noticeable effects of the environment are on depth of visibility
and the surrounding colour. On the surface on a clear day we can see the
horizon 20 miles away. On a good day in the Red Sea we can see 50 metres.
On a bad afternoon in the Galapagos the density of the plankton in the water
may prevent us from seeing beyond 5 metres. The plankton will of course appear
as a myriad of particles in your picture.
And if you dive around the UK, then the particles turn the water green as
well as reducing the visibility.
(Low visibility in Farnes) |
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Water absorbs light quite rapidly and does this according to
the colour of the light. At a depth of only 3 metres most of the red light
has been absorbed and a red object will appear dark brown. At 10 metres most
of the colours have been absorbed and the level of light has fallen drastically.
At 30 metres only residual blue light remains. It is possible to account
for these colour changes down to a 'depth plus camera-to-subject' distance
of about 10 metres by means of coloured (orange/red) filters and adjustment
of the camera's white balance. Once set for any combination of depth plus
C>S distance, any positive or negative variation in depth or distance
from the subject implies either a bluish or reddish tinge to the picture.
At depths greater than 15 metres, the picture starts to adopt an uncorrectable
bluish tinge. At depths greater than 20 metres, it is frequently necessary
to reduce the number of filters used in order to allow for the reduction
in overall level of available light; this will increase the bluish tinge.
It is sometimes possible to use video lights, but the ones that can be afforded
by amateurs are really only suitable for subjects that are very close to
the lens. Other advanced options include taking down mirrors - held by your
buddy - to reflect additional light onto the subject. Remember to ask your
buddy to carry a sheet of white plastic so that you can white balance your
camera; alternatively wear white fins. |
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You can video anything that is down there, but if you don't
want colour tinges, it should be within 3 metres of your lens. You will need
a wide-angle lens to video large creatures e.g. sharks, divers and shoals
of fishes. Close ups of these creatures can be shot with a standard lens.
Small creatures, say 2 cm long, can be shot with a standard lens but you
must place the lens only a few centimetres from the subject. Very small
creatures, e.g. pygmy sea horse require special lenses and the camera mounted
on a tripod. The whole scene should usually have a shallow depth of field.
This requirement results from the fact that if the depth of field is large
then the surround to the subject will appear blue, OK if the background is
water, but not if it is coral. |
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© words and images, JohnFletcher
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