Contributed by: C@tz
The term
?macrophotography? normally refers to images in which
the subject is presented at a larger than normal size --
a ratio greater than 1 to 1. True macrophotography,
however, requires that the distance between the lens and
the image plane be greater than the distance between the
lens and the subject. For film cameras, macrophotography
requires the use of special accessories such as bellows
or macro adapters that will magnify the image. Special
macro lenses, usually more expensive than their
non-macro counterparts, are specially designed to get
very close, and yet avoid distortions. Some telephoto
lenses also offer a "macro" capability, by an optical
formulation that allows the lens to still reach focus,
while close to the subject.
One of the benefits of
digital cameras is that many of them are able to do
excellent macro photography. In certain cases, some
cameras can come amazingly close to the subject, in
others, the zoom is used to magnify the subject and fill
the frame. Generally speaking, the shutter speeds will
be very slow, and a stable platform is a good idea.
Additionally, using the camera's self-timer will prevent
camera shake that can easily ruin a shot.
Extreme close-up views can be a lot of fun and
also be very useful. Getting in close to an object will
generally reveal details the eye tends to ignore.
Familiar objects become unusual shapes, textures, and
colours reminiscent of modern art or architecture. As
mentioned earlier, an extreme close-up is the equivalent
of looking at something with a magnifying glass. Details
normally invisible suddenly jump out and can offer an
increased appreciation of the subject. Your buds, for
example, can be wonderful subjects. Whatever the use,
macrophotography presents two major challenges: one is
the shallowness of the
depth of field a lens
provides when it is very close to the subject, and the
other is the difficulty encountered in
lighting a
subject evenly to avoid shadows.
Depth of
field: Depth of field refers to the correctly
focused or sharp zone in an image. The depth of field is
most affected by the aperture of a lens. A small
aperture (larger f-numbers) provides a greater depth of
field than a large aperture (small f-numbers). With
compact cameras that do not offer the possibility of
changing lenses, the camera and lens combination is also
important, as each camera will have a specific minimum
focus; check your manual to determine these
specifications. Furthermore, most compact digital
cameras do not allow the user to select the aperture the
camera uses. This means that unless the subject is
brightly lit, the camera will probably select a larger
aperture, shortening the depth of field in the process.
In many cases, this will be a sharp zone ranging from a
few millimetres (fractions of an inch) up to
approximately 10 cm (3"+).
To deal with a
shallow depth of field it is important to position the
subject and the camera so they are parallel to each
other (see illustration at right). Maintaining as close
to a parallel as possible is the best way to ensure that
the depth of field stays uniform throughout the image.
With the lenses commonly used with compact digital
cameras, lens distortion can become pronounced in
close-ups. Lens distortions such as barrelling and pin
cushioning are the most common. If you notice distortion
in a macro photo, it does not mean there is something
wrong with the lens or your camera, only that the lens
was not designed with macrophotography as its primary
use. Simply avoid strong vertical or horizontal lines in
your composition, or, use any distortion to enhance the
image. Macrophotography and extreme close-ups often
cause perspective distortions, just like wide-angle
lenses do. The trick is to use them to your advantage.
Lighting: The second challenge of
macrophotography for the photographer is to provide even
lighting to the subject of the image. This can become
quite difficult when the camera is very close to the
subject. Often, flash cannot be used effectively as it
will either alter the colour of the photo or, more
likely, cause an overexposure by being too close to the
subject. In these cases, it is best to turn off the
flash, and provide another source of light. When
outside, sunlight and one or two small mirrors acting as
reflectors can be used successfully to remove shadows.
Indoors, good results can be obtained with everyday
household lamps and with simple reflectors. Note though,
that you may have to correct the image's colour to
reduce the yellow light incandescent lighting will add.
If mirrors are not available, a piece of white cardboard
will work well, reflecting the light softly on the
subject. Another variation involves wrapping the
cardboard with shiny aluminium foil to increase its
reflectivity. If necessary, more reflectors can be used
so the light is distributed equally on the object. If
your camera has a zoom lens, you may not have to be
extremely close to the subject. This is particularly
useful in cases where it is impossible to light the
object properly, an optical zoom allows you to move the
camera back, light the subject properly and still get a
full-frame image. Beware of camera shake when using a
zoom to do close-ups, it is often advisable to stabilise
the camera on a tripod.
(1) The red line
indicates the focal plane and the
green zone the
focusing plane.
(2) Small pieces of
reflective cardboard and a mirror are
used to light
the subject evenly. The tripod stabilises
the
camera.
(3) Here, the flower is lit by
natural light. The use of
white cardboard spreads
the light , eliminating harsh shadows.
(4) The same coin with three different
light sources
Bottom: halogen and flash.
Middle:
halogen only.
Top: flash only.
A digital camera is one of the best
ways to take macro pictures; some cameras are able to
get as close as an inch (2 to 3 cm). The added bonus of
being able to see the image instantly means that it is
possible to improve it easily if needed. Experimentation
is the best guide, so go ahead, and see what your camera
can do!
