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Faults
by
Linda Pitkin
Reproduced
from in focus 25 (Dec.
1987)
A
resumé of the Basic Course talk given at the October
meeting
It
is very satisfying to take photos that other people like,
especially if you can produce photos that will earn money
or win competitions, But ultimately a good photograph must
be one that will please the photographer and if you are happy
with your efforts then there is no need to be put off if others
don't appreciate them, A fault is only a fault when it produces
a result you don't like. The important thing is to get to
know which situations will produce a particular result so
that you can avoid them or use them as you please.
There
are so many things that can go wrong in underwater photography
that I cannot attempt to cover them all, but here is a small
sample of the faults I have come up against and a few suggestions
as to how to avoid them.
Technical
Faults
Some
faults are clearly technical and relatively straightforward
to correct. Assembling your camera set-up carelessly can lead
to some annoying faults, not to say floods. Vignetting sometimes
occurs when wide-angle lenses are not seated fully, with the
result that the corners of the photo are cut off. Supplementary
close-up lenses and their framers can work loose, if not fitted
properly, so that the area framed no longer corresponds with
the area photographed. Worse still is if the lens and framer
drop off altogether when you are not paying attention! Incidentally,
close-up framers sometimes throw a distracting shadow onto
the photo, particularly when the background is pale e.g. sand.
This can be overcome by removing the framer or by taking the
subject against a darker background.
It
is always worth checking your camera settings at the start
of a dive even if you have already checked them on land. Controls
can so easily be knocked when you hit the water. A commonerror
(of mine at any rate) is that the camera speed can be accidently
moved from the flash synchronisation setting (1/60th of a
second in likonos cameras). Nikonos cameras have a mechanical
shutter and the flash is oparated by the shutter opening.
At speeds greater than 1/60th of a second, e.g. 1/125th of
a second, the shutter has not had time to open fully and only
part of the frame is exposed to the flash. The faster the
shutter speed, the smaller the part of the frame exposed to
the flash. This fault can also happen even when the camera
speed setting is synchronised with the flash. For instance
a flood - even a very slight one - can cause corrosion on
the shutter mechanism, and grease on the shutter blades can
also affect their movement, so look after your camera carefully
and test the flash synchronisation from time to time. Otherwise
you may be blissfully unaware that your balanced light shots
will turn out to be plain silhouettes. A silhouette can of
course be very effective in Its own right if the subject lends
itself to that sort of treatment. If you have had a flood
and are congratulating yourself on having got the camera going
again, don't trust it until you have run a test film. A hint
of condensation in a lens may escape your notice until you
see the misty results on film!
Wide-angle
15 mm lenses are expensive, even second-hand, but much cheaper
alternatives are available. These are supplementary lenses,
which fit onto the standard 35m and include the Vizmaster.
This is excellent in many respects but one thing you need
to watch out for when you use it is flare, which can appear
in the photo if you shoot towards a bright light source such
as the sun (a problem that rarely arises in British waters).
I am told that you can use this flare to artistic advantage
but in my experience it always happens in the wrong place.
Lighting
Faults
Lighting
is a constant source of problems in underwater photography
because conditions are so variable. Automatic flashguns can
solve many of the problems, so too can operating at a fixed
distance. This is what you do with macro and close-up photography
with a Nikonos camera and it is a good way to start out because
you can run a test film and then stick to one exposure and
get reasonable results with most subjects. Adjustments must
be made for particularly light or dark subjects though and
don't forget to consider the background too.
When
you are taking photos at varying distances, you can get used
to judging more or less the right exposures with a bit of
practice, even if you don't have an automatic flash or use
a light meter. Looking towards the sun and very near the surface
the amount of natural light can be surprising though. It is
safer to bracket several shots, especially if you don't use
a light meter. At dusk or at night, dark coloured subjects
need to be well lit or they can easily result in underexposed
pictures. Transparent subjects are always difficult to light
so that they show up well; positioning the flash well to one
ride or even slightly behind the subject is more effective
than trying to light it from in front. It is worth bracketing
the exposure when you are experimenting with the flash in
different positions because it can be a bit hit-and-miss.
It is easy to overexpose silvery fish because, unlike transparent
creatures, they reflect back too much light, although you
are unlikely to notice this until a light Is shone on them.
Make allowances for this by reducing the exposure or try photographing
silvery fish by natural light.
Backscatter
is a constant bugbear in British waters but you can do something
to reduce the problem. Mounting or holding the flash to one
side of the camera, the further away the better, reduces the
amount of sediment that is lit-up between the lens and the
subject. A narrow bean of light is an advantage over a diffused
light in poor-visibility conditions. Using natural light instead
of flash can help to minimise backscatter in the photo. If
you cannot get rid of backscatter it is comforting to consider
that it can actually improve a picture (well occasionally
anyway) by adding a bit of sparkle in the right place.
Focusing
Faults
Once
you are satisfied with the exposure, there are still things
that can go wrong with focusing. If you and your subject are
both being washed about in a swell focusing or judging distance
can be difficult. It helps if you try to catch a moment when
things are relatively stationary and persevere with repeated
attempts. You cannot always wait for a fast-moving fish to
stop swimming though. If it is lit solely by flash the outline
should be fairly sharp since the flash is of short enough
duration to freeze most of the movement, but the outline will
be blurred If photographed with natural light. A balanced-light
photo will result in an image with a double outline part produced
by flash and part by natural light. Panning (following the
movement with the camera) will correct this to give a sharp
image of the subject, though in doing this you sacrifice sharpness
of the background, since moving the camera will blur this.
Composition
Faults
With
housed SLR cameras there is no excuse for mistakes in framing
the subject, but with a Nikonos framing is not so easy. For
close-up and macro work there are frames but with wide-angle
lenses you are likely to be using a viewfinder that does not
correspond exactly with the photo. The difference between
the two viewpoints is parallax and this can make all the difference
to the composition. It isn't much of a problem with distant
views but the closer you get, the bigger the discrepancy.
Some viewfinders can be set to correct for parallax at varying
distances, with others you have to learn to judge the correction
you need to make.
When
you have overcome the more obvious technical problems of underwater
photography there still remains the problem of how to take
a good photograph as opposed to one that is merely in focus
and correctly exposed. Bad composition is perhaps the worst
of all faults. Mia Buehr's talk at the October meeting gave
an excellent insight into this subject, which is too vast
a field to go into in detail here.
It
is all too easy to blame the subject when the photo looks
a mess, whether it is a fish which insisted on turning Its
back or a model diver who perversely swam the wrong way. One
approach to overcoming this problem is to plan the shot in
advance, which can work well if you are using your own props
or models or if you are tackling scenic photos of a site you
are familiar with. It is not always possible to plan with
less predictable underwater life. Taking photos of fish and
other creatures can be difficult but you can improve the chances
in your favour by Setting to know your subject's behaviour.
Most animals are upset by contact and are reluctant to be
your underwater model, understandably if it means being chased
out of their comfortable resting-place to be dazzled by flashes
and jabbed at with close-up frames.
The
rates of pay are not usually too good either although I know
of one large Napoleon Wrasse in the Red Sea who will agree
to pose only on payment of one hard-boiled egg per photo.
Generally, though, the best way to overcome the problem of
unco-operative subjects is to show them a little sympathy,
patience and understanding. This can make all the difference
between an unappealing photo and a successful one, Firstly,
try not too disturb the creature too much as you approach
it but if it still curls up and sulks give it a few minutes
to recover its poise and it will pose in a much more relaxed
and confident manner. This applies not just to fish that can
swim away but to animals like corals too. It only takes a
light brush against a coral to cause the flower-like polyps
to retract leaving the branches looking bare and dead. Groups
of animals such as shoals of fish look untidy if you blunder
into them and make then disperse in all directions. Wait for
them to swim in formation. Animals that are active at night
are easily upset not Just by contact but by bright lights
so It is a mistake to shine a powerful torch on them. Be ready
to catch the subject at that split-second when it is looking
its best. Sometimes only a slight difference in position can
make a vast difference to the end result. Taking a series
of photos is always advisable as you can usually improve an
the first attempt,
It
is all too easy to ignore what is going on in the background
when you are concentrating on a subject but it is important
to pay attention to everything that will be In the frame.
It is fine for your subject to merge in with the background
if you want to show how well-camouflaged it is but in general
it is effective to make the subject stand out. One way of
achieving this is to take a low-profile view which will isolate
the subject from the background. Using a small aperture will
produce a dramatic black backdrop to details of structure
in close-up photography, but if you prefer your photos to
have an obvious underwater look you might consider this a
fault. An alternative, if you can get an uninterrupted view
of water behind the subject, is to use a larger aperture to
give a balanced light effect,
A
common mistake is for the subject to be too small in the frame
and to look lost. Use the right lens for the subject or pick
a suitable sized subject for the lens, Getting in close to
the subject gives dramatic impact not just because of the
size but also because it enhances the colour and crispness
of the Image because there is less water between lens and
subject to absorb colour and obscure detail. Colour density
can be increased by slightly underexposing the shot (by not
more than 1/3 stop).
When
you have lined up your shot don't hesitate too long before
pressing the shutter; unwelcome intruders such as fish have
an unfortunate tendency to stray into the frame at the last
minute and you my be too busy looking at the main subject
to even notice. It is a good idea to keep an eye on fellow
divers as well if only to make sure that they don't pop up
unexpectedly in the middle of your composition. Divers are
notoriously difficult to photograph well. If you haven't trained
them to pose successfully they usually look awkward and it
is sometimes best to catch them unawares when they are behaving
naturally,
Even
when you have got everything right and taken your prizewinning
photo you are not home and dry. Things can still go wrong
at the processing stage. I lost ny enthusiasm for home processing
after someone took the wrong lid off the container in the
middle of the operation. Kodak have a better record but even
they have been known to produce an occasional processing fault
such as a thin blue line running through the frames
Having
taken taken your photographs, with or without faults, don't
Just stick them in the back of a cupboard but keep looking
at them. Don't despair - you can learn a lot from the bad
ones as well as the good ones. And, of course, you can always
use them to give a talk on 'Faults'! |
