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Close-up
and macro photography
by
Mia Buehr
Reproduced
from in focus 12 (Oct.
1985)
A
resumé of the Basic Course Talk in August
One
of the most annoying of the frustrations lying in wait for
the novice underwater photographer is the fact that, in spite
of spending a small fortune on a good camera and flash, one
all too often finds it impossible to take good pictures. The
Nikonos, excellent camera though it is, does require some
experience to use it to its full potential. There are a lot
of decisions to be made underwater, and the beginner is bound
to get some of them wrong. The consequence will be a poor
picture and a very frustrated photographer. But there is a
way for even the most inexperienced of photographers to produce
first rate pictures from the first roll of film, and to continue
to get good pictures while becoming experienced in the complex
techniques of underwater photography. The secret- Use a close-up
system with the Nikonos and spend your first photographic
season in mastering its use. At the end of the year you should
have a nice portfolio of photos to show for your efforts,
as well as a lot of valuable experience.
The
Nikonos 35 mm lens is unable to focus closer than 0.8 metre,
or 2.75 feet. Though that may sound very near it is a considerable
distance to the underwater caneraq and that mere metre of
water between subject ana camera can cause a lot of photographic
problems. To focus closer than this, however, you need a separate
close up attachment. There are basically two types: supplementary
lenses and extension tubes.
SUPPLEMENTARY
LENSES
Supplementary
lenses are clamped on the front of the Nikonos lens. Their
strength is measured in diopters (for example - 1, 2 or 3
diopters as the lenses increase in strength). Depending on
their strength, they will enable your Nikonos to focus from
round about 15 inches to roughly 6 inches in front of the
lens. Perhaps the most popular supplementary lenses on the
market are either the Nikonos close-up lens (which can be
used with the 35 mm, 28 mm or 8Omm lens) or the Ocean Optics
001 lens (which can be used with the 35 mm or 28 mm lens).
EXTENSION
TUBES
Another
way to make the Nikonos focus closer than the standard 0.8
metre is to move the 35 mm lens away from the film by fitting
an extension tube between the lens and the camera body. Photography
with extension tubes is often called 'macro photography',
and usually involves taking pictures of subjects extremely
close to the lens: subject-caiiera distance is usually of
the order of 3 to 6 inches. Extension tubes are often defined
in terms of their 'reproduction ratio'. This is the relation
between the size of the subject, and the size that the subject
appears on the transparency. The 35 mm lens has a reproduction
ratio of approximately 20 : 1 that is 20 units of the field
seen by the camera are reduced to 1 unit on the slide.
Extension
tubes can reduce this to 1 : 1 or 2 : 1 (in which objects
are reduced to and 1/2 life size on the slide), 1 1 (where
objects are life size on the slide), or even 1 : 2 (in which
the object is magnified two times).
WHICH
TO USE?
So
both supplementary lenses and extension tubes will turn the
Nikonos into a close-up camera. Which is the better system
for the novice photographer- The short answer is that it all
depends on what sort of pictures the photographer wants to
take, because the two systems don't quite do the same thing.
Sup-plementary lenses are fitted to the outside of the Nikonos
lens. They can be removed and replaced underwater$ and so
give the photographer the choice between a normal lens and
a close-up system on the same dive. A supplementary lens will
let the camera focus roughly a foot in front of the lens,
and so take pictures of subjects about 6 to 10 inches across,
such as a ,;ea urchin, a crab, or a large sponge. The addition
of a supplementary lens in front of the Nikonos lens may cause
some small degree of distortion, but usually this is scarcely
noticeable. Extension tubes, on the other hand, are fitted
between the camera body_and the camera lens and so are not
removable underwater: you're stuck with the system you start
the dive with. Tubes let you focus very close to the lens
and are ideal for taking pictures of tiny subjects such as
individual jewel anemones, hydroids or nudibranchs. As there
is no optical interference with the Nikonos lens, the photographic
quality of pictures taken with extension tubes is usually
excellent.
So
in practice, supplementary lenses and extension tubes are
suited to different purposes. Use a supplementary lens for
larger subjects or when you want an adaptable system, and
fit extension tubes when you're hunting the smaller subjects.
Whether you use a lens or a 'macro system'# the practical
problems of close-up photography are similar. In the first
place, all close,up systems have a limited depth of field.
In an extreme close-up (such as a 1 : 1 or 1 : 2 extension
tube) you'll have to take great care to select subjects that
lie roughly in one plane: otherwise only a small part of your
subject will be in focus. Another potential problem is viewfinding.
The standard Nikonos viewfinder is useless for close-up work,
as it will 'look' far beyond the field covered by your system
(the problem of parallax).
FRAMERS
But
the differences, both of focus ing and viewfinding, are solved
by the provision of the frame or pointers, with which all
close-up systems are fitted. These devices define the field
of view that will appear on your picture, and so let you compose
your photo with great accuracy. Also, any close-up frame or
pointer will show you precisely the plane of focus of the
system. Briefly, if a subject is in the plane of the frame,
or right at the tip of the pointer, it will be in focus.
So
a close-up system can solve two of your technical problems
(focus ing and viewfinding) straightaway. But you'll still
have to determine what exposure to use (that is, what
or f-stop). There are no hard and fast rules about this; you'll
just have to find out by trial and error what is right for
your particular system. The beet way to go about this is to
shoot off a test film, taking pictures of several different
subject6 using all the apertures that your lens will give
you. Then have a look at the film and decide on the two (or
possibly three) best exposures, and use these two (or three)
apertures for all your future work. Taking two or three exposures
of each subject ('bracketing') will ensure that you get at
least one that is properly exposed.
LIGHTING
When
setting up a close-up system, give some thought to the flash
that you'll use (you will need a flash; close up photography
can't really be done with ambient light). But you needn't
buy a very powerful and expensive flash: a small one will
do just as well and probably even better. Because the subject
is so close to the camera you need less light to illuminate
it properly than you'd have to use to take pictures of things
further off, and indeed a very powerful flash may well prove
to be too strong for close-up work. An autoflash isn't necessary
(exposures are pretty predictable in close-up work) but if
you have oneg it should work perfectly well on the auto mode.
When
it comes to mounting the flash on the camera you may find
that you can break one of the basic rules of underwater photography.
'With most systems it is important to keep the flash as far
away from the camera as possible in order to reduce the reflection
of light into the lens from particles suspended in the water
(the problem of backscatter). In close-up photography you
can keep the camera quite close to the flash and still have
no backscatter problems. This is partly because there is very
little water (and so very little suspended matter) between
subject and camera, and partly because the flash - subject
- lens angle is very wide, so any backscatter tends to be
reflected back into the flash rather than the lens. The fact
that there is little water between subject and camera also
means that the problem caused by the effects of water on light
(such as absorption and diffusion) are minimised, and close-up
photographs usually have brilliant colours, crisp contrasts
and generally good picture quality.
CHOICE
OF SUBJECT
So
the close-up system is easy to use because ao many technical
problems don't exist (is backscatter and light diffusion),
or are catered for by the sytem (ie focussing and framing)
or can easily be predicted (exposure). But easy as it is to
use, a few basic rules must be followed if you want to get
the best results. First, because depth of field can be very
limited, you should try and find fairly flattish subjects.
The more extreme your degree of close-up, the more important
it is that your subject should lie in the same plane as the
end of your framing device. Also, the frame that makes your
viewfinding so easy can cause problems by casting shadows
on your subject, so be sure that your flash is allowed an
unobstructed view of the subject. But perhaps the biggest
challenge to the novice photographer is learning to choose
appropriate and original subjects for the close-up system.
There are count less small animals in the sea: anemones, little
crabs, snails, small fish, and of course the endlessly fascinating
nudibranchs. But small parts of large animals can also make
very attractive pictures: masses of anemone tentacles, the
tube feet of an urchin, a section of an encrusting sponge
or colonial sea squirt.
Though
the close-up camera is an excellent introduction to underwater
photography for the novice, it can still offer many challenges
to the more experienced photographer. There are opportunities
to experiment with unusual flash angles and backlighting,
and tomanipulate background effects. The colours, textures
and shapes of close-up subjects provide endless possibilities
of picture construction and composition that can be difficult
to obtain with other formats. So if you are a novice photographer,
a close-up system can't be bettered as an introduction to
underwater photography, and when you've moved out of the novice
class you'll still need close-up to get those pictures and
effects that no other system can give you.
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